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wii freeloader wii freeloader bootdisc developed datel circumvent regional lockout wii video game console allows playing games regions allow use dvd±r commonly used backups copies homebrew used combination modchip allow compatibility games use update blocker user enters bootdisc wii system launches application wii menu replaces disc region-locked game disc disc allows user play foreign gamecube games issues reported different signals games simply working foreign system even use wii freeloader wii games one version game disc siliconera reported north american version video game played japanese wii using wii freeloader switch play japanese version game system
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Operating systems
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default password device needs username and/or password log default password usually provided allows device accessed initial setup resetting factory defaults manufacturers equipment typically use simple password admin password equipment ship expectation users change password configuration default username password usually found instruction manual common devices device default passwords one major contributing factors large-scale compromises home routers leaving password devices available public huge security risk devices wireless routers come unique default router username passwords printed sticker secure option common default password vendors however derive password device mac address using known algorithm case password also easily reproduced attackers access internet connected devices network user must know default ip address manufacturers typically use codice_1 also codice_2 default router ip address however variations similarly login details leaving unchanged lead security issues
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Computer security
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nsite software nsite a.k.a nsite.com nsite software platform service company based bay area specializing sales force enhancements although several pre-built applications offered platform promising part nsite ability customer use product develop application using simple internet-based interface since 2006 part sap business objects company claimed 27,000 customers worldwide acquired sap business objects november 2006 flagship product subscription-based nsite platform components provide quote proposal order management custom development platform ajax front-end ms-sql back-end paul tabet co-founded nsite 1998 together others chief executive officer 2002 2002 alf goebel announced ceo two years later bob jandro announced new ceo nsite grew 27,000 customers height success started downward spiral shortly sap business objects acquisition finally met end 2010 announced retirement
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Distributed computing architecture
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grgen grgen.net software development tool offers programming languages domain specific languages optimized processing graph structured data core languages consists modular graph rewrite rules built declarative graph pattern matching rewriting supplemented many constructs used imperative object-oriented programming completed language devices known database query languages graph rewrite generator compiles languages efficient cli assemblies via c -code intermediate step integrated via api code written .net-language grgen executed windows linux mono needed open source available lgpl v3 rapid prototyping debugging interactive shell vcg- graph viewer included package languages visual stepwise debugging grgen allows one develop natural level abstraction graph-based representations employed engineering model transformation computational linguistics compiler construction intermediate representation grgen increases productivity kinds tasks far beyond achieved programming traditional programming language due many implemented performance optimizations still allows one achieve high-performance solutions authors claim system offers highest combined speed development execution available algorithmic processing graph-based representations based performance regarding diverse tasks posed different editions transformation tool contest /grabats example containing graph model rule specifications grgen.net-solution antworld-case posed grabats 08 graph model rewrite rules
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Programming language topics
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apple software restore apple software restore asr command line utility mac os x used apply dmg disk image selected partition mount point file system often used cloning large numbers macintosh computers apple software restore read image locally server via http multicast asr // uri asr two methods use restore image volume either copy items file-by-file mode directly block-copy image latter method need go os filesystem much faster typically limited speed drives network connections involved order use faster method .dmg file involved must first checksummed cases files re-ordered inside image also done tool graphical disk utility uses asr processes background perform restores
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Operating systems
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internet server application programming interface internet server application programming interface isapi n-tier api internet information services iis microsoft collection windows-based web server services prominent application iis isapi microsoft web server isapi also implemented apache mod_isapi module server-side web applications written microsoft iis used apache third-party web servers like zeus web server offer isapi interfaces microsoft web server application software called internet information services made number sub-applications configurable asp.net one slice iis allowing programmer write web applications choice programming language vb.net c f supported microsoft .net clr isapi much lower-level programming system giving much better performance expense simplicity isapi consists two components extensions filters two types applications developed using isapi filters extensions must compiled dll files registered iis run web server isapi applications written using language allows export standard c functions instance c c++ delphi couple libraries available help ease development isapi applications delphi pascal intraweb components web-application development mfc includes classes developing isapi applications additionally atl server technology includes c++ library dedicated developing isapi applications isapi extensions true applications run iis access functionality provided iis isapi extensions implemented dlls loaded process controlled iis clients access isapi extensions way access static html page certain file extensions complete folder site mapped handled isapi extension isapi filters used modify enhance functionality provided iis always run iis server filter every request find one need process filters programmed examine modify incoming outgoing streams data internally programmed externally configured priorities determine order filters called filters implemented dlls registered iis server site level global level i.e. apply sites iis server filters initialised worker process started listens requests site installed common tasks performed isapi filters include list common isapi applications implemented isapi extensions isapi applications developed using development tool generate windows dll wizards generating isapi framework applications available microsoft development tools since visual c++ 4.0
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Operating systems
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mackeeper mackeeper utility software distributed kromtech alliance known heavily promoted aggressive advertising affiliate marketing mackeeper faced class-action lawsuit company allegedly deceived users paying unneeded fixes lawsuit settled 2015 us 2 million without admission guilt company five major versions mackeeper released first beta version mackeeper 0.8 released 13 may 2010 mackeeper 1.0 released october 26 2010 mackeeper 2.0 released 30 january 2012 macworld – iworld expanded number utilities related security data control cleaning optimization kromtech alliance acquired mackeeper zeobit april 2013 mackeeper 3.0 released june 2014 software service new human expert feature optimization os x yosemite july 2018 mackeeper 4.0 released mackeeper initially developed 2009 zeobit april 2013 zeobit sold mackeeper kromtech alliance corp. kromtech closely affiliated zeobit ukraine hired many former kiev-based zeobit employees december 2015 security researcher chris vickery discovered publicly accessible database 21gb mackeeper user data internet exposing usernames passwords information 13 million mackeeper users according kromtech result server misconfiguration error fixed within hours discovery integrates avira anti-malware scanning engine versions opened critical security hole filesystem-level encryption tool encrypt files folders password data recovery utility permits users recover unintentionally deleted files backup software also included copy files usb flash drive external hdd ftp server data erasure permits users permanently delete files although pc world argues feature duplicates secure empty trash feature formerly built macos disk cleaner finds removes junk files hard drive order free space earlier bundles received mixed reviews reviewers divided effectiveness software macworld gave mackeeper 3.5 5 stars august 2010 based 0.9.6 build program found reasonably priced set tools experienced lagging switching tools maclife rated 2.5 5 said useful mainly freeing drive space found features offered inconsistent results believed users ’ need antivirus feature av-comparatives found mackeeper excellent ability detect mac-based malware noted well suited enthusiasts good understanding security issues ideal non-expert users need pre-configured optimal security macs opswat awarded program gold certification protecting users anti-phishing attempts well spyware malware zeobit claims negative attacks launched mackeeper unnamed competitor many users press confusing mackeeper another application reviews latest software version largely negative may 2015 test pc world found mackeeper identified need extensive corrections brand new fully patched machines december 2015 business insider imore suggested users avoid product install top ten reviews removed mackeeper top 10 ranking noting software features competitors performance mac malware identification tests showed software better detection rates resulting score 7.5 10 july 2017 av-test assessment found mackeeper detected 85.9 percent tested malware mackeeper criticized difficult uninstall tom guide macworld published how-to guides deleting software according macworld users frequently ask get rid mackeeper sophos malwarebytes competing vendors kromtech anti-virus software market identified mackeeper potentially unwanted program sophos reported mackeeper 2017 prolific macos potentially unwanted program macworld observed aggressive mackeeper advertising leads people believe software either malware scam neither macworld also notes pop-up pop-under ads may due third-party installers computerworld described mackeeper virulent piece software promises cure mac woes instead makes things much worse softonic.com described software perfect genuinely useful also noting mackeeper exaggerates threat associated user security app multiple reviewers criticized zeobit marketing promotional techniques kromtech buys upwards 60 million ad impressions month making one largest buyers web traffic aimed mac users zeobit accused employing misleading advertising regard promotion mackeeper including aggressive affiliate marketing pop-under ads planting sockpuppet reviews well websites set discredit competitors kromtech also issues affiliate advertisers attracted 50 percent commissions kromtech pays sales mackeeper wrapped mackeeper ads adware 2018 kromtech began take steps affiliate marketers said scamming users january 2014 class action lawsuit filed zeobit illinois lawsuit alleged neither free trial full registered versions mackeeper performed credible diagnostic testing reported consumer mac need repair at-risk due harmful error may 2014 lawsuit filed zeobit pennsylvania alleging mackeeper fakes security problems deceive victims paying unneeded fixes 10 august 2015 zeobit settled class action lawsuit customers bought mackeeper 8 july 2015 apply get refund kromtech also filed least two unsuccessful lawsuits perceives defaming july 2013 kromtech filed lawsuit macpaw developers cleanmymac kromtech alleged macpaw employees created several usernames posts several websites defaming mackeeper software case dismissed hearing year later 2014 kromtech filed lawsuit david a. cox alleging defamed kromtech calling mackeeper fraudulent application youtube video judge dismissed case lack personal jurisdiction july 2016 kromtech sent cease desist letter luqman wadood 14-year old technology reviewer alleged harassment slander mackeeper brand number youtube videos luqman said videos diplomatic
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Computer security
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mail transfer protocol mail transfer protocol mtp obsolete network protocol defined rfc 780 used reliably transfer email tcp udp ports 57 allocated mtp allocation removed iana simple mail transfer protocol smtp defined rfc 788 replaced mail transfer protocol
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Internet protocols
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galeon galeon discontinued gecko-based web browser created marco pesenti gritti goal delivering consistent browsing experience gnome desktop environment gained popularity early 2000s due speed flexibility configuration features disagreement future galeon split development team 2002 resulted departure browser initial author several developers event marked beginning browser popularity decline led discontinuation september 2008 galeon features subsequently ported epiphany called web – descendant galeon galeon made use gecko features including configuration options standards support apart galeon several features uncommon browsers time project started marco pesenti gritti goal creating web browser would fast consistent gnome desktop environment first public version galeon 0.6 released june 2000 first releases galeon criticised lack basic features cookie proxy support though browser added features every release version 1.2 galeon introduced many new features drew attention general public time galeon creation popular linux browsers including netscape mozilla large multi-functional programs made slow start often impractical due high memory usage processor requirements opera somewhat faster proprietary software distributed trialware adware versions lacked functionality microsoft windows version galeon widely seen one best linux browsers available polls revealed substantial usage share galeon though popularity regarded owing lack stability evident mozilla browsers release new version gtk+ widget toolkit used construct user interface galeon team decided write new version galeon scratch time gnome project adopted new human interface guidelines promoted simplicity uniform design galeon team differing opinions new guidelines author lead developer marco pesenti gritti endorsed saw rewrite opportunity make galeon simpler many developers believed reducing number preferences simplifying user interface would harm project november 2002 result several discussions topic gritti made decision cease work galeon fork project started development hig-compliant web browser called epiphany known web gritti longer controlled development galeon previous functionality restored subsequent releases new features added though development got slow split time rising popularity firefox status default browser major distribution overwhelming number extensions led decline galeon user base eventually galeon developers announced plans halt development galeon saying current approach unsustainable regarding resources required maintain instead planned develop set extensions epiphany provide similar functionality even development ceased september 2008 browser remained popular december 2011 still available linux distribution repositories debian 6 squeeze although part debian 7 wheezy galeon praised customizability speed compared netscape navigator firefox though konqueror opera still faster older hardware galeon noted session handling crash recovery november 2002 osnews conducted poll determine popular gecko-based browser included several browsers microsoft windows mac os x linux n't include netscape navigator mozilla suite linux-only galeon second popular cross-platform firefox time known phoenix critics noted galeon tricky plugin installation
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Internet protocols
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sentence extraction sentence extraction technique used automatic summarization text shallow approach statistical heuristics used identify salient sentences text sentence extraction low-cost approach compared knowledge-intensive deeper approaches require additional knowledge bases ontologies linguistic knowledge short sentence extraction works filter allows important sentences pass major downside applying sentence-extraction techniques task summarization loss coherence resulting summary nevertheless sentence extraction summaries give valuable clues main points document frequently sufficiently intelligible human readers usually combination heuristics used determine important sentences within document heuristic assigns positive negative score sentence heuristics applied highest-scoring sentences included summary individual heuristics weighted according importance seminal papers laid foundations many techniques used today published hans peter luhn 1958 h. p edmundson 1969 luhn proposed assign weight sentences beginning document paragraph edmundson stressed importance title-words summarization first employ stop-lists order filter uninformative words low semantic content e.g grammatical words also distinguished bonus words stigma words i.e words probably occur together important e.g word form significant unimportant information idea using key-words i.e words occur significantly frequently document still one core heuristics today summarizers large linguistic corpora available today tf–idf value originated information retrieval successfully applied identify key words text example word cat occurs significantly often text summarized tf term frequency corpus idf means inverse document frequency corpus meant document cat likely important word text text may fact text cats
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Computational linguistics
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generic security services application program interface generic security service application program interface gssapi also gss-api application programming interface programs access security services gssapi ietf standard addresses problem many similar incompatible security services use today gssapi provide security instead security-service vendors provide gssapi implementations usually form libraries installed security software libraries present gssapi-compatible interface application writers write application use vendor-independent gssapi security implementation ever needs replacing application need rewritten definitive feature gssapi applications exchange opaque messages tokens hide implementation detail higher-level application client server sides application written convey tokens given respective gssapi implementations gssapi tokens usually travel insecure network mechanisms provide inherent message security exchange number tokens gssapi implementations ends inform local application security context established security context established sensitive application messages wrapped encrypted gssapi secure communication client server typical protections guaranteed gssapi wrapping include confidentiality secrecy integrity authenticity gssapi also provide local guarantees identity remote user remote host gssapi describes 45 procedure calls significant ones include gssapi standardized c rfc 2744 language java implements gssapi jgss java generic security services application program interface limitations gssapi include standardizes authentication authorization assumes client–server architecture anticipating new security mechanisms gssapi includes negotiating pseudo mechanism spnego discover use new mechanisms present original application built dominant gssapi mechanism implementation use kerberos unlike gssapi kerberos api standardized various existing implementations use incompatible apis gssapi allows kerberos implementations api compatible
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Operating systems
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sparc t4 sparc t4 sparc multicore microprocessor introduced 2011 oracle corporation processor designed offer high multithreaded performance 8 threads per core 8 cores per chip well high single threaded performance chip chip 4th generation processor t-series family sun microsystems brought first t-series processor ultrasparc t1 market 2005 chip first sun/oracle sparc chip use dynamic threading out-of-order execution incorporates one floating point unit one dedicated cryptographic unit per core cores use 64-bit sparc version 9 architecture running frequencies 2.85 ghz 3.0 ghz built 40 nm process die size eight core eight thread per core chip built 40 nm process running 2.5 ghz described sun microsystems processor roadmap 2009 codenamed yosemite falls given expected release date late 2011 processor expected introduce new microarchitecture codenamed vt core online technology website register speculated chip would named t4 successor sparc t3 yosemite falls cpu product remained oracle corporation processor roadmap company took sun early 2010 december 2010 t4 processor confirmed oracle vp hardware development designed improved per-thread performance eight cores expected release within one year processor design presented 2011 hot chips conference cores renamed s3 vt included dual-issue 16 stage integer pipeline 11-cycle floating point pipeline giving improvements previous s2 core used sparc t3 processor core associated 16 kb data 16 kb instruction l1 caches unified 128 kb l2 cache eight cores share 4 mb l3 cache total transistor count approximately 855 million design first sun/oracle sparc processor out-of-order execution first processor sparc t-series family include ability issue one instruction per cycle core execution units t4 processor officially introduced part oracle sparc t4 servers september 2011 initial product releases single processor t4-1 rack server ran 2.85 ghz dual processor t4-2 ran 2.85 ghz frequency quad processor t4-4 server ran 3.0 ghz sparc s3 core also include thread priority mechanism called dynamic threading whereby thread allocated resources based need giving increased performance s3 core resources shared among active threads 8 shared resources include branch prediction structures various buffer entries out-of-order execution resources static resource allocation reserves resources threads based policy whether thread use dynamic threading allocates resources threads ready use thus improving performance cryptographic performance also increased t3 chip design improvements including new set cryptographic instructions ultrasparc t2 t3 per-core cryptographic coprocessors replaced in-core accelerators instruction-based cryptography implementation designed achieve wire speed encryption decryption sparc t4 10-gbit/s ethernet ports architectural changes claimed deliver 5x improvement single thread integer performance twice per-thread throughput performance compared previous generation t3 published specjvm2008 result 16-core t4-2 454 ops/m 321 ops/m 32-core t3-2 ratio 2.8x performance per core
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Computer architecture
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benoit schillings benoit schillings belgian software engineer distinguished engineer google x leading early projects x known one lead developers operating system beos noted amateur astronomer schillings association inc. began 1990 developer software apple macintosh visited apple expo paris met jean-louis gassée gassée left apple computer found asked schillings become second engineer would work operating system new computer called bebox schillings accepted offer starting march 1991 developed file system known old file system ofs associated user-space database application called zookeeper indexed metadata file system file system fast efficient later replaced dominic giampaolo file system schillings also developed graphics system beos known app server well programming frameworks interface kit application kit used software developers write software operating system joining trolltech october 2005 schillings worked distinguished engineer cto openwave mike reed led team developed version 7 openwave phone suite mobile phone applications benoit also ran android ios mobile teams yahoo 2013 2017
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Operating systems
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dragon msx dragon msx msx 1 home computer designed radofin creators mattel aquarius dragon data well known dragon 64 home computer clone trs-80 color computer rare prototypes ever built
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Computer architecture
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anthony james barr anthony james barr born september 24 1940 aka tony barr jim barr american programming language designer software engineer inventor among notable contributions statistical analysis system sas automated lumber yield optimization automated classification medical entities acme widely used internationally science government industry academia sas system founded barr 1966 september 1966 athens georgia presented conceptual ideas sas members committee statistical software university statisticians southern experiment stations usses barr earlier created analysis-of-variance modeling language inspired notation statistician maurice kendall developed assembly language ibm 1410 graduate student north carolina state university 1962 1963 dr. a. grandage author ibm 650 analysis-of-variance programs advised statistical computations followed multiple regression program flexible input format algebraic transformation variables 1963 1964 drawing programs along experience structured data files created sas placing statistical procedures formatted file framework barr experience structured data files gained working formatted file system see 1966 1968 barr developed fundamental structure language sas 1968 barr began collaboration others barr designed implemented programming language data management report writing systems areas evolving system 1976 sas institute inc. incorporated anthony j. barr james h. goodnight john p. sall jane t. helwig barr holding largest share 40 sold shares 1979 barr created acme program national center health statistics 1967 1969 acme computer program assigns one underlying cause death based multiple causes death listed death certificate acme conjunction components comprise mortality medical data system mmds system used uniformly determine underlying cause death death certificates united states acme become de facto international standard automated selection underlying cause death components mmds variations used many nations around world system provides essential data used calculating mortality statistics 1971 1972 barr along partner sandy mullin designed patented built first computerized equipment optimize usage lumber furniture industry device read marked flaws board calculated cross rip cuts required optimal board usage marked cut lines board 1973 barr-mullin inc. incorporated lumber yield optimization technology remains widely used american wood industry 1968 barr created first non-ibm linking loader ibm/360 named ldr loader sponsored american data processing inc. raleigh north carolina barr loader cut typical program testing times twenty-five percent ibm offer equivalent loader eighteen months barr loader commercially available 1971 barr created first non-ibm hasp terminal emulator marketed university computing company ucc hasp emulator gave significant performance increase ibm 2780 emulator developed ucc 1969 emulators developed pdp-8 minicomputer allowed cope terminals communicate ibm/360 ibm/370 1971 barr also implemented hasp workstation computer industries orange california implemented data general nova minicomputer program became singer corporation remote batch terminal singer ucc sold terminal divisions harris corporation continued market products 1983 barr developed hardware software performing hasp remote job entry communication ibm pc company barr systems inc. marketed sold barr hasp went implement support bisync sna sdlc workstations gateways along data communications output management products barr employed ibm federal systems division pentagon washington d.c. 1964 1966 worked nips formatted file system ffs generalized data base management system retrieval report writing one first data management systems take advantage defined file structure data storage retrieval efficiency assigned work national military command center information processing branch joint chiefs staff barr rewrote enhanced ffs implementing three five major components retrieval sorting file update work featured innovation uniform lexical analyzer languages system uniform method handling error messages working ffs introduced barr potential defined file structure become central concept sas barr born new york city grew summit new jersey graduated summit high school 1958
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Programming language topics
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memory pool memory pools also called fixed-size blocks allocation use pools memory management allows dynamic memory allocation comparable malloc c++ operator new implementations suffer fragmentation variable block sizes recommendable use real time system due performance efficient solution preallocating number memory blocks size called memory pool application allocate access free blocks represented handles run time many real-time operating systems use memory pools transaction processing facility systems like web server nginx use term memory pool refer group variable-size allocations later deallocated also known region see region-based memory management simple memory pool module allocate example three pools compile time block sizes optimized application deploying module application allocate access free memory following interface benefits drawbacks
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Operating systems
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templeos templeos formerly j operating system sparrowos losethos biblical-themed lightweight operating system designed third temple prophesied bible created american programmer terry a. davis developed alone course decade series episodes later described revelation god system characterized modern x86-64 commodore 64 using interface similar mixture dos turbo c. davis proclaimed system features 640x480 resolution 16-color display single audio voice explicitly instructed god programmed original variation c named holyc place basic included original flight simulator compiler kernel templeos released 2013 last updated 2017 received largely favorable reviews tech communities davis amassed small online following died august 11 2018 terry a. davis 1969–2018 began experiencing regular manic episodes 1996 leading numerous stays mental hospitals initially diagnosed bipolar disorder later declared schizophrenic remained unemployed rest life suffered delusions space aliens government agents left briefly hospitalized mental health issues experiencing self-described revelation proclaimed direct communication god god told operating system god third temple davis began developing templeos circa 2003 one early names j operating system renaming losethos reference scene 1986 film platoon 2008 davis wrote losethos primarily making video games networking internet support far 'm concerned would reinventing wheel another name used sparrowos settling templeos mid-2013 website announced god temple finished god kills cia spreads davis died hit train august 11 2018 templeos 64-bit non-preemptive multi-tasking multi-cored public domain open source ring-0-only single address space non-networked pc operating system recreational programming os runs 8-bit ascii graphics source code 2d 3d graphics library run 640x480 vga 16 colors like modern operating systems keyboard mouse support supports iso 9660 fat32 redsea file systems last created davis support file compression according davis many specifications—such 640x480 resolution 16-color display single audio voice—were instructed god explained limited resolution make easier children draw illustrations god operating system includes original flight simulator compiler kernel one bundled program egypt game player travels burning bush use high-speed stopwatch stopwatch meant act oracle generates pseudo-random text something davis likened ouija board glossolalia example generated text follows templeos written programming language developed davis c c++ called holyc holyc variation c developed davis programming language templeos used interact shell write execute entire applications shell ide comes templeos supports several features embedding images code uses non-standard text format known doldoc support hypertext links images 3d meshes embedded otherwise regular ascii files file spinning 3d model tank comment source code code jit-compiled davis ultimately wrote 100,000 lines code os templeos received mostly favorable reviews tech journalist david cassel opined partly programming websites tried find necessary patience understanding accommodate davis techrepublic osnews published positive articles davis work even though davis banned latter hostile comments targeting readers staff review techrepublic james sanders concluded templeos testament dedication passion one man displaying technological prowess n't need anything osnews editor kroc kamen wrote os shows computing still hobby everybody serious days want code os uses interpretive dance input method allowed companies like apple damned 2017 os shown part outsider art exhibition bourogne france davis death osnews editor thom holwerda wrote davis clearly gifted programmer – writing entire operating system small feat – sad see affected mental illness one fan described davis programming legend another computer engineer compared development templeos one-man-built skyscraper engineer previously spoken davis length believed davis could steve jobs steve wozniak illness added actually boggles mind one man wrote hard lay person understand phenomenal achievement write entire operating system alone another computer engineer said templeos contained innovations developer accomplished particularly runs certain part computer processor maintain extremely quick speed
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Operating systems
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frank pfenning frank pfenning professor computer science adjunct professor department philosophy head computer science department carnegie mellon university received ph.d. carnegie mellon university department mathematics 1987 dissertation entitled proof transformations higher-order logic student peter b. andrews research includes work area programming languages logic type theory logical frameworks automated deduction trustworthy computing one principal authors twelf system also developed carnegie mellon introductory imperative programming course undergraduates c0 programming language used course 2015 named fellow association computing machinery contributions logical foundations automatic theorem proving types programming languages competitive squash player ranked top five university squash ladder
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Programming language topics
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mc-lag mc-lag multi-chassis link aggregation group type link aggregation group lag constituent ports terminate separate chassis primarily purpose providing redundancy event one chassis fails ieee 802.1ax-2008 industry standard link aggregation mention mc-lag preclude implementation varies vendor notably protocol existing chassis proprietary 2012 ieee created standardized alternative mc-lag ieee 802.1aq shortest path bridging lag link aggregation group method inverse multiplexing multiple ethernet links thereby increasing bandwidth providing redundancy defined ieee 802.1ax-2008 standard states link aggregation allows one links aggregated together form link aggregation group mac client treat link aggregation group single link layer 2 transparency achieved lag using single mac address device ’ ports lag group lag configured either static dynamic dynamic lag uses peer-to-peer protocol control called link aggregation control protocol lacp lacp protocol also defined within 802.1ax-2008 standard lag implemented two ways lag n lag n+n lag n load sharing mode lag lag n+n provides worker standby flavour lag n protocol automatically distributes load balances traffic across working links within lag thus maximising use group ethernet links go come back providing improved resilience throughput different style resilience 2 nodes complete implementation lacp protocol supports separate worker/standby lag subgroups lag n+n worker links group fail standby links one links worker group fail note lacp marks links standby mode using sync flag mc-lag adds node-level redundancy normal link-level redundancy lag provides allows two nodes share common lag endpoint multiple nodes present single logical lag remote end note mc-lag implementations vendor-specific cooperating chassis remain externally compliant ieee 802.1ax-2008 standard nodes mc-lag cluster communicate synchronize negotiate automatic switchovers failover implementations may support administrator-initiated manual switchovers diagram shows four configurations ha configuration superior spanning tree load shared across links normal operation whereas spanning tree must disable links prevent loops following table lists known vendor implementations mc-lag proprietary
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Internet protocols
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kasidet pos ram scraper malware kasidet pos malware variant point sale pos malware performs ddos attacks using namecoin dot-bit service scrape payment card details also known trojan.mwzlesson neutrino found september 2015 cyber security experts combination backdoor.neutrino.50 pos malware kasidet pos worm gets system along malware gets downloaded unknowingly user visits malicious websites malware different pos malware scrapes data advanced features first scrapes pos ram steals payment card details scraped information sent cyber criminal intercepted get post requests browser difficult detect bot using security programs sometimes detectable email spam campaigns exploit kits scraping capability kasidet enhanced cyber criminals hides c c server namecoin dns service dot-bit
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Computer security
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parabola gnu/linux-libre parabola gnu/linux-libre operating system i686 x86-64 armv7 architectures based many packages arch linux arch linux arm distinguishes former offering free software includes gnu operating system components common many linux distributions linux-libre kernel instead generic linux kernel parabola listed free software foundation completely free operating system true free system distribution guidelines parabola uses rolling release model like arch regular system update needed obtain latest software development focuses system simplicity community involvement use latest free software packages parabola originally proposed members gnewsense irc channel 2009 members different arch linux communities especially spanish-speaking members started development maintenance project software documentation may 20 2011 parabola distribution recognized completely free project gnu making part fsf list free distributions february 2012 dmitrij d. czarkoff reviewed parabola osnews czarkoff reported test computer number hardware problems surfaced due lack free firmware said effectively means many devices supported parabola eg. installing acer aspire one 531h netbook could n't use broadcom bluetooth module intel wifi/wimax link 5150 adapter still could use htc magic custom gingerbread rom usb 3g/wifi modem though something always connected usb port pretty annoying laptop specifically netbook czarkoff also criticized lack documentation available parabola concluded overall impression parabola gnu/linux user experience exactly matches one arch system easy flexible installation configuration process good choice free software packages though lack documentation spoils user experience arch linux resources used configure extend distribution hardware would allow would probably stick parabola parabola used mips64el port provide support chinese loongson processor used lemote yeeloong laptop discontinued due lack resources interest final activity seen july 2014 robert rijkhoff reviewed parabola gnu/linux distrowatch september 2017 project uses 100 free software official arch repositories i686 x86-64 architectures official arch arm repositories except alarm aur armv7 uses free replacements possible linux-libre kernel instead generic linux kernel filtering process removes around 700 software packages repositories meet requirements free software definition architecture parabola established social contract parabola social contract commits project free software community viewing competing nonfree systems free culture democracy follow arch philosophy covenant included gnu free system distribution guidelines two ways install parabola either scratch using installable iso images migrating existing arch-based system latter process almost simple switching parabola repositories list talkingparabola derivative install cd based talkingarch respin parabola iso modified include speech braille output blind visually impaired users talkingparabola retains features parabola live image adds speech braille packages make possible blind visually impaired users install parabola eyes-free parabola community created number cartoon characters project characters gnu cat named bola conceived parabola main characteristics elegant minimalist lightweight
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Operating systems
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gw-basic gw-basic dialect basic programming language developed microsoft basica originally compaq otherwise identical microsoft/ibm basica fully self-contained executable need rom basic bundled ms-dos operating systems ibm pc compatibles microsoft microsoft also sold basic compiler bascom compatible gw-basic programs needing speed language suitable simple games business programs like since included versions ms-dos also low-cost way many aspiring programmers learn fundamentals computer programming release ms-dos 5.0 gw-basic place eventually taken qbasic interpreter part separately available quickbasic compiler ibm basica gw-basic largely ports mbasic version 5.x added features specifically ibm pc hardware common features basic-80 5.x basica/gw-basic include ability crunch program lines omitting spaces common feature earlier microsoft basic implementations removed basic-80 5.x basica/gwbasic basic-80 programs using peek/poke statements would run gw-basic basica added large number features ibm pc sound graphics memory commands features present basic-80 included ability execute rnd function parameters ability also save programs protected format preventing listed basica also allowed double-precision numbers used mathematical trigonometric functions cos sin atn n't allowed 8-bit versions basic feature normally enabled required optional parameter /d startup i.e codice_1 basic memory footprint slightly increased used microsoft offer generic version ms-dos v3.20 1986 variants operating system oem versions depending oem basic distributed either basica.exe gwbasic.exe former confused ibm basica always came .com file variants basic extra features support particular machine example tandy versions dos included special gw-basic supported enhanced sound graphics capabilities initial version gw-basic one included compaq dos 1.13 released compaq portable 1983 analogous ibm basica 1.10 used cp/m-derived file control blocks disk access support subdirectories later versions added feature improved graphics capabilities gw-basic 3.20 1986 added ega graphics support version basica gw-basic vga support effect last new version released superseded qbasic buyers hercules graphics cards received special version gw-basic card utility disk called hbasic added support 720×348 monochrome graphics versions basica/gw-basic support hercules graphics could display graphics card use third-party cga emulation simcga gw-basic command line-based integrated development environment ide based dartmouth basic using cursor movement keys line displayed screen edited also includes function key shortcuts bottom screen like early microcomputer versions basic gw-basic lacked many structures needed structured programming local variables gw-basic programs executed relatively slowly interpreted language program lines must numbered non-numbered lines considered commands direct mode executed immediately program source files normally saved binary compressed format tokens replacing keywords option save ascii text form gw-basic command-line environment commands codice_2 current program quit operating codice_3 commands also used program statements little support structured programming gw-basic codice_4 conditional statements must written one line although codice_5 statements may group multiple lines functions defined using single line codice_6 statement e.g. codice_7 data type variables specified character end variable name codice_8 string characters codice_9 integer etc groups variables also set default types based initial letter name use codice_10 etc. statements default type undeclared variables identified typing statements single-precision floating point 32-bit mbf gw-basic allowed use joystick light pen input devices gw-basic read write files com ports also event trapping ports since cassette port interface original ibm pc never implemented compatibles cassette operations supported gw-basic play simple music using codice_11 statement needing string notes represented music macro language e.g. codice_12 low-level control possible codice_13 statement takes arguments frequency hertz length clock ticks standard internal pc speaker ibm machines consequently sound limited single channel beeps whistles befits 'business machine home-based pcs like tandy 1000 allowed three channels sound codice_13 codice_11 commands several theories initials gw stand greg whitten early microsoft employee developed standards company basic compiler line says bill gates picked name gw-basic whitten refers gee-whiz basic unsure gates named program microsoft user manual microsoft press also refers name may also nicknamed gee-whiz large number graphics commands common theories initials origins include graphics windows gates william microsoft president time gates-whitten two main designers program
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Programming language topics
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gt racing cockpit gt racing cockpit see trademark symbols difference name line gran turismo official video game racing cockpits designed sparco logitech a.k.a logicool japan collaboration polyphony digital official kits co-designed released japan logicool sparco distributed import tuner endless north america compatible kits designed released worldwide european manufacturers playseats movetech fia homologated driving simulation cockpit line sku lpsk standing logicool playstation sparco kit official kits logicool auto part maker sparco joint designed sparco racing cockpit/seat official wheels gt force wheels although gt force wheels supported professional oriented playseats compatible kits line playseats based upon different design e.g g25 racing wheel playseats kit includes parts named gearshift holder seat slider sparco racing cockpit official kit original gt force gran turismo 3 a-spec released japan 2001 kits two parts named steering pod bucket chair official product steering pod features sparco gran turismo double name emblem plate sparco speed seat gt logos official kit gt force pro gran turismo 5 prologue sparco racing cockpit pro fighter model released december 22 2003 japan first kit one features emblem plate logos racing cockpit pro kits specially designed gt force pro wheel compatible models including prior gt force wheels updated version gt force pro gran turismo 4 kit released june 10 2004 japan kit replaces fighter seat gran turismo custom sparco speed seat evolution speed bucket seat still features official sparco gran turismo plate logos released june 2005 endless sku north american licensed version racing cockpit pro hence srcp sparco racing cockpit pro seat kit frame e.g steering floor mat steering pod official sparco gran turismo plate available though sparco sprint bucket seat north american version lpsk-02002 though replaces fighter bucket seat similar sparco model called sprint although sparco gran turismo plate included sparco seat regular one gt logo larger individuals version type 1 simultaneously released north american market version called sparco siena reclinable seat type 2 replaces regular bucket seat larger retractable model called siena srcp-001 kit sparco seat gt custom
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Computer architecture
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hindi-to-punjabi machine translation system hindi punjabi machine translation system developed punjabi university patiala gurpreet singh lehal dr. vishal goyal aimed translate hindi text punjabi text based direct approach includes preprocessing text normalization replacing collocations replacing proper nouns translation engine identifying surnames identifying titles lexicon lookup word-sense disambiguation inflection analysis transliteration post processing module system available online
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Computational linguistics
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counterspy software counterspy proprietary spyware removal program microsoft windows software developed sunbelt software counterspy scans pc spyware examining files hard drive objects memory windows registry cookies capability called dnr resuscitate according sunbelt improves chances killing resuscitators past tool based used giant antispyware engine program currently version 3.1 sunbelt software released version 2 includes revamped interface smaller memory footprint available download 15-day trial version effective may 23 2011 counterspy discontinued longer available purchase
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Computer security
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iasme iasme governance information assurance standard designed simple affordable help improve cyber security small medium-sized enterprises smes iasme governance technical controls aligned cyber essentials scheme certification iasme standard includes certification cyber essentials iasme governance standard developed 2010 proven effective improving security supply chains large organisations standard maps closely international iso/iec 27001 information assurance standard iasme governance originally developed academic-sme partnership attracted lot interest government small businesses research towards iasme model undertaken uk 2009-10 acknowledgement current international information assurance standard iso/iec 27001 complex resource-strapped smes providing weakness supply chain iasme developed 2010-11 launched later year revised regularly keep pace changes risk environment smes development process smes explained published international sme conference paper iasme governance standard follows implementation pattern used international standards community including pdca plan-do-check-act principles information security management system isms provides management framework refined expressed business terms recognisable organisations sizes iasme governance standard developed piloted help small businesses mostly west midlands uk encouraging results standard shown useful smes uk internationally large organisations use iasme governance standard supply chains understand reduce supplier risk article explaining supply chain benefits written developer david booth large small organisations use iasme certification alternative iso/iec 27001 standard standard managed iasme consortium ltd operate network 150 certification bodies licensed certify candidate organisations question set free anyone download without registration licensed creative commons by-nc-nd license standard available two levels assurance 2017 standard updated include additional questions enable organisations comply general data protection regulations gdpr iasme governance standard covers following information security topics iasme governance risk-led standard similar set controls annex iso/iec 27001 standard iasme governance maps closely uk government ncsc 10 steps cyber security mapping two standards available cyber assessment framework caf developed uk government allow organisations demonstrate compliance nis directive iasme governance standard maps closely caf nhs digital data security protection toolkit online self-assessment tool allows organisations measure performance national data guardian ’ 10 data security standards iasme governance maps closely toolkit majority topics iasme standard become focus attention information security threat uk businesses continues increase vulnerabilities systems continue cause expensive data breaches system failures increasing number newspaper journal articles subject reflect increased security awareness recognised states jersey suitable security standard government supply chain iasme specifically mentioned keynote speech infosec europe 2013 event held london received innovation award computer weekly europe shortly afterwards.. april 2019 iasme awarded cyber business year prestigious uk national cyber awards
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Computer security
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acorn network computer acorn network computer network computer type thin client designed manufactured acorn computers ltd implementation network computer reference profile oracle corporation commissioned acorn specify network computers detail history see acorn network computer sophie wilson acorn led effort launched august 1996 ncos operating system used first implementation based risc os ran arm hardware manufacturing obligations achieved contract fujitsu subsidiary d2d 1997 acorn offered designs cost licensees netstation available two versions one modem home use via television version ethernet card use businesses schools vga monitors on-site bsd unix fileserver based riscbsd early arm port netbsd versions upgradable modem ethernet cards replaceable podules acorn-format eurocards home version trialled 1997/98 conjunction bt used supported pal ntsc svga displays identical specifications used strongarm sa-110 200mhz processor arm7500-based desklite launched 1998 acorn continued produce arm-based designs demonstrating first strongarm prototype may 1996 6 months later evolved concord launched late 1997 designs included set-top box nc second generation network computer operating system longer based risc os instead consisted netbsd 1.2.1 code later ncs produced based intel pentium architecture netstation planned ship smart card enable internet banking
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Computer architecture
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borland database engine borland database engine bde windows-based core database engine connectivity software behind borland delphi c++builder intrabuilder paradox windows visual dbase windows borland ’ turbo pascal database toolbox add-on beginning borland compiler add-ons facilitated database connectivity came paradox engine windows – pxengwin – could compiled program facilitate connectivity paradox tables first dll-based connectivity engine odapi open database api represented borland ’ attempt centralise connectivity suite applications included brand-new paradox windows 4 quattro version 4.5 5.0 paradox windows database engine crystallised idapi 2000 borland introduced new sql driver architecture called dbexpress deprecated bde sql links technology 2014 embarcadero removed bde installer rad studio xe7 install making separate download order strengthen message bde deprecated number years programmers using bde encouraged update software use newer database connectivity technologies like embarcadero firedac third party provided solutions included set database drivers enables consistent access standard data sources paradox dbase foxpro access text databases add microsoft odbc drivers needed built-in odbc socket optionally borland sql links product provides access range database management systems dbms including informix db2 interbase oracle sybase bde object-oriented design runtime application developers interact bde creating various bde objects runtime objects used manipulate database entities tables queries bde application program interface api provides direct c c++ optimized access database engine well bde built-in drivers dbase paradox foxpro access text databases core database engine files consist set dlls fully re-entrant thread-safe included bde set supplemental tools examples sample code bde system configured using bde administrator bdeadmin.exe included bde borland local sql subset ansi-92 sql enhanced support paradox dbase standard naming conventions tables fields called columns sql local sql lets use sql query local standard database tables reside database server well remote dbms servers local sql also essential make multi-table queries across local standard tables remote sql servers older name bde api integrated database application program interface idapi
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Databases
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application portfolio attack surface realm application security term application portfolio attack surface apas refers collective risk organization posed sum total security vulnerabilities found within set mission critical systems software run organization enterprise
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Computer security
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r800 cpu r800 central processing unit used msx turbo-r home computer r800 designed ascii corporation japan built mitsui co. ltd.. goals fastest cpu possible maintaining compatibility old msx zilog z80-based hardware software order preserve software compatibility old msx software r800 uses superset z80 instruction set addition z80 opcodes two multiplication instructions added mulub 8-bit muluw 16-bit also many undocumented z80 instructions made official including opcodes dealing ix iy 8-bit registers ixh ixl iyh iyl r800 based directly z80 stems z800 family lacks undocumented z80 features instance undocumented flags represented bits 3 5 f register n't assume values z80 causing fail zexall tests undocumented opcode often called sll alias sla instruction hardware side radical changes made internal 4-bit alu z80 replaced new 16-bit alu opcodes like add hl bc previously took 11 clock cycles run fast one bus cycle conditions maximum cpu clock speed also increased 14.32 mhz—four times fast original 3.57 mhz z80 used msx bus clock increased 7.16 mhz data bus remained 8-bit maintain compatibility old hardware additional changes made way cpu fetches opcodes original z80 uses 4 cycles fetch simple instruction like additional waitstate issued msx architecture review z80 fetch mechanism typical msx environment needed understand r800 since implementations msx use ram memory disposed 256×256 bytes block two cycles required set address fetch r800 avoids remembering last known state higher 8-bits next instruction 256-byte boundaries higher 8-bits set cycle saved however z80 refresh cycles destroy information higher bits workaround needed solution used r800 refresh entire blocks ram instead refreshing one line ram instruction issued 30μs cpu halted 4μs time used refresh block ram since refresh fetch instructions waitstate removed due faster ram chips simple instructions issued using one cycle cycle would cycle 2 z80 example cycle 1 becomes optional issued program crosses 256-byte boundary applies fast ram used msx turbor external hardware connected cartridge slots uses timings similar z80 even internal rom turbor fast enough fetch scheme additional chips turbor mirror contents rom ram order make run faster
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Computer architecture
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chromebit chromebit dongle running google chrome os operating system placed hdmi port television monitor device turns display personal computer chromebit allows adding keyboard mouse bluetooth wi-fi device announced april 2015 began shipping november chromebit turns display hdmi port desktop variant chromebook laptop runs google chrome os operating system chrome os primarily supports single application web browser thereby relying heavily internet connection software functionality data storage chromebits superficial resemblance chromecast another google device whereas chromecast designed display video still images television large-screen display chromebit self-contained personal computer device compete intel compute stick offers similar plug-in functionality using two operating systems windows 8.1 ubuntu internally first chromebit resembles standard chromebook laptop device features 802.11ac wi-fi bluetooth 4.0 well usb 2.0 port one end end swivels enabling fit variety hdmi slots google announced chromebit march 31 2015 google asus began shipping first model november
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Distributed computing architecture
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sam76 sam76 macro programming language used late 1970s present 2007 initially ran cp/m sam76 language list string processor designed interactive user-directed applications including artificial intelligence programming permits high portability machine machine language shares certain features common lisp forth shell programming languages unix operating system claude a. r. kagan language developer sought combine within single interpretive processor characteristics two different string general-purpose macro generators provisions embed multiple infix operator mathematical systems sam76 designed language based around idea programming macros user define macro code word defined user invoke specific set instructions perform routine within program execute set instructions usually either machine assembly language use macro program way user need define routine particular operation string required user substitute macro name since language rewritten c compiles windows unix linux similar operating systems source code available online still compiles runs 2006 sam76 language follows well defined syntax easy learn read relies heavily however system symbols replace pseudo english words basic pascal sam76 interpreter also provides highly reactive interactive language almost converse user task task consequently language capability performing complex operations program control text editing manipulation gaming simulation mathematics features similar lisp forth list processors sam76 also capability functioning query language providing powerful human machine interaction uses keyboard data interaction modify shape future responses language also capable growing extension like lisp logo almost difference procedures data structures procedures treated data acted upon procedures even procedures defined different users new procedures mapped created behave language primitives inherent functions language like logo means new users create separate vocabularies saved executed adding language vocabulary providing individual customization
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Programming language topics
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list android launchers list android launchers presents main view device responsible starting apps hosting live widgets 51 lyse kim 8 march 2019 go launcher popular android launcher retrieved original 28 february 2019
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Operating systems
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zfs+ zfs+ combined file system logical volume manager software subsystem initially released common development distribution license cddl based zfs originally developed sun microsystems proprietary data deduplication features added greenbytes subsequently made proprietary storage system product greenbytes originally owned trademark zfs+ confused zfs trademark currently held oracle corporation greenbytes owned oracle greenbytes created storage appliance called cypress nas filer originally based upon sun microsystems x86-64-based sun fire x4500 platform bundled zfs+ implementation value-add technology greenbytes claimed zfs+ technology could reduce storage power consumption 50 2009 greenbytes relaunched technology new name gbfs greenbytes file system
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Computer file systems
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internet control message protocol ipv6 internet control message protocol version 6 icmpv6 implementation internet control message protocol icmp internet protocol version 6 ipv6 icmpv6 defined rfc 4443 icmpv6 integral part ipv6 performs error reporting diagnostic functions e.g. ping framework extensions implement future changes several extensions published defining new icmpv6 message types well new options existing icmpv6 message types neighbor discovery protocol ndp node discovery protocol ipv6 replaces enhances functions arp secure neighbor discovery send extension ndp extra security multicast listener discovery mld used ipv6 routers discovering multicast listeners directly attached link much like internet group management protocol igmp used ipv4 multicast router discovery mrd allows discovery multicast routers icmpv6 messages may classified error messages information messages icmpv6 messages transported ipv6 packets ipv6 next header value icmpv6 set value 58 icmpv6 message consists header protocol payload header contains three fields type 8 bits code 8 bits checksum 16 bits type specifies type message values range 0 127 high-order bit 0 indicate error message values range 128 255 high-order bit 1 indicate information message code field value depends message type provides additional level message granularity checksum field provides minimal level integrity verification icmp message control messages identified value type field code field gives additional context information message messages serve purpose correspondingly named icmp message types note table comprehensive current complete list assigned icmpv6 types found link iana icmpv6 parameters icmpv6 provides minimal level message integrity verification inclusion 16-bit checksum header checksum calculated starting pseudo-header ipv6 header fields according ipv6 standard consists source destination addresses packet length next header field latter set value 58 following pseudo header checksum continued icmpv6 message checksum computation performed according internet protocol standards using 16-bit ones complement summation followed final ones complement checksum inserting checksum field note differs way calculated ipv4 icmp similar calculation done tcp icmpv6 node receives packet must undertake actions depend type message icmpv6 protocol must limit number error messages sent destination avoid network overloading example node continues forward erroneous packets icmp signal error first packet periodically fixed minimum period fixed network maximum load icmp error message must never sent response another icmp error message
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Internet protocols
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java api xml-based rpc java api xml-based rpc jax-rpc allows java application invoke java-based web service known description still consistent wsdl description jax-rpc one java xml programming apis seen java rmis web services jax-rpc 2.0 renamed jax-ws 2.0 java api xml web services jax-rpc 1 deprecated java ee 6 jax-rpc service utilizes w3c world wide web consortium standards like wsdl web service description language works follows advantage method allows web service implemented server-side servlet ejb container thus servlet ejb applications made available web services
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Web technology
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cyberattack computers computer networks attack attempt expose alter disable destroy steal gain unauthorized access make unauthorized use asset cyberattack type offensive maneuver targets computer information systems infrastructures computer networks personal computer devices attacker person process attempts access data functions restricted areas system without authorization potentially malicious intent depending context cyberattacks part cyberwarfare cyberterrorism cyberattack employed nation-states individuals groups society organizations may originate anonymous source cyberattack may steal alter destroy specified target hacking susceptible system cyberattacks range installing spyware personal computer attempting destroy infrastructure entire nations legal experts seeking limit use term incidents causing physical damage distinguishing routine data breaches broader hacking activities cyberattacks become increasingly sophisticated dangerous user behavior analytics siem used help prevent attacks since late 1980s cyberattacks evolved several times use innovations information technology vectors committing cybercrimes recent years scale robustness cyberattacks increased rapidly observed world economic forum 2018 report offensive cyber capabilities developing rapidly ability deal hostile incidents may 2000 internet engineering task force defined attack rfc 2828 cnss instruction 4009 dated 26 april 2010 committee national security systems united states america defines attack increasing dependencies modern society information computers networks private public sectors including military led new terms like cyber attack cyberwarfare cnss instruction 4009 define cyber attack first six months 2017 two billion data records stolen impacted cyberattacks ransomware payments reached double 2016 cyberwarfare utilizes techniques defending attacking information computer networks inhabit cyberspace often prolonged cyber campaign series related campaigns denies opponent ability employing technological instruments war attack opponent critical computer systems cyberterrorism hand use computer network tools shut critical national infrastructures energy transportation government operations coerce intimidate government civilian population means end result cyberwarfare cyberterrorism damage critical infrastructures computer systems linked together within confines cyberspace three factors contribute cyber-attacks launched state individual fear factor spectacularity factor vulnerability factor spectacularity factor measure actual damage achieved attack meaning attack creates direct losses usually loss availability loss income garners negative publicity 8 february 2000 denial service attack severely reduced traffic many major sites including amazon buy.com cnn ebay attack continued affect still sites next day amazon reportedly estimated loss business 600,000 vulnerability factor exploits vulnerable organization government establishment cyber-attacks organizations without maintenance systems might running old servers vulnerable updated systems organization vulnerable denial service attack government establishment defaced web page computer network attack disrupts integrity authenticity data usually malicious code alters program logic controls data leading errors output professional hackers either working employed government military service find computer systems vulnerabilities lacking appropriate security software vulnerabilities found infect systems malicious code remotely control system computer sending commands view content disrupt computers needs pre-existing system flaw within computer antivirus protection faulty system configuration viral code work many professional hackers promote cyberterrorists new set rules govern actions cyberterrorists premeditated plans attacks born rage need develop plans step-by-step acquire appropriate software carry attack usually political agendas targeting political structures cyber terrorists hackers political motivation attacks impact political structure corruption destruction also target civilians civilian interests civilian installations previously stated cyberterrorists attack persons property cause enough harm generate fear attack active passive attack perpetrated insider outside organization term attack relates basic security terms shown following diagram resource physical logical called asset one vulnerabilities exploited threat agent threat action result confidentiality integrity availability resources may compromised potentially damage may extend resources addition one initially identified vulnerable including resources organization resources involved parties customers suppliers so-called cia triad basis information security attack active attempts alter system resources affect operation compromises integrity availability passive attack attempts learn make use information system affect system resources compromises confidentiality threat potential violation security exists circumstance capability action event could breach security cause harm threat possible danger might exploit vulnerability threat either intentional i.e. intelligent e.g. individual cracker criminal organization accidental e.g. possibility computer malfunctioning possibility act god earthquake fire tornado set policies concerned information security management information security management systems isms developed manage according risk management principles countermeasures order accomplish security strategy set following rules regulations applicable country attack led security incident i.e security event involves security violation words security-relevant system event system security policy disobeyed otherwise breached overall picture represents risk factors risk scenario organization make steps detect classify manage security incidents first logical step set incident response plan eventually computer emergency response team order detect attacks number countermeasures set organizational procedural technical levels computer emergency response team information technology security audit intrusion detection system example attack usually perpetrated someone bad intentions black hatted attacks falls category perform penetration testing organization information system find foreseen controls place attacks classified according origin i.e conducted using one computers last case called distributed attack botnets used conduct distributed attacks classifications according procedures used type vulnerabilities exploited attacks concentrated network mechanisms host features attacks physical i.e theft damage computers equipment others attempts force changes logic used computers network protocols order achieve unforeseen original designer result useful attacker software used logical attacks computers called malware following partial short list attacks detail number techniques utilize cyber-attacks variety ways administer individuals establishments broader scale attacks broken two categories syntactic attacks semantic attacks syntactic attacks straightforward considered malicious software includes viruses worms trojan horses virus self-replicating program attach another program file order reproduce virus hide unlikely locations memory computer system attach whatever file sees fit execute code also change digital footprint time replicates making harder track computer worm need another file program copy self-sustaining running program worms replicate network using protocols latest incarnation worms make use known vulnerabilities systems penetrate execute code replicate systems code red ii worm infected 259 000 systems less 14 hours much larger scale worms designed industrial espionage monitor collect server traffic activities transmit back creator trojan horse designed perform legitimate tasks also performs unknown unwanted activity basis many viruses worms installing onto computer keyboard loggers backdoor software commercial sense trojans imbedded trial versions software gather additional intelligence target without person even knowing happening three likely attack individual establishment emails web browsers chat clients remote software updates semantic attack modification dissemination correct incorrect information information modified could done without use computers even though new opportunities found using set someone wrong direction cover tracks dissemination incorrect information utilized two instances india pakistan involved cyberspace conflicts started 1990s earlier cyber attacks came known early 1999 since india pakistan engaged long-term dispute kashmir moved cyberspace historical accounts indicated country hackers repeatedly involved attacking computing database system number attacks grown yearly 45 1999 133 2000 275 end august 2001 2010 indian hackers laid cyber attack least 36 government database websites going name indian cyber army 2013 indian hackers hacked official website election commission pakistan attempt retrieve sensitive database information retaliation pakistani hackers calling true cyber army hacked defaced ~1,059 websites indian election bodies according media pakistan working effective cyber security system program called cyber secure pakistan csp program launched april 2013 pakistan information security association program expanded country universities within cyberwarfare individual must recognize state actors involved committing cyber-attacks one another two predominant players discussed age-old comparison east versus west china cyber capabilities compared united states capabilities many state non-state actors involved cyberwarfare russia iran iraq al qaeda since china u.s. leading foreground cyberwarfare capabilities two state actors discussed q2 2013 akamai technologies reported indonesia toppled china portion 38 percent cyber attack high increase 21 percent portion previous quarter china set 33 percent us set 6.9 percent 79 percent attack came asia pacific region indonesia dominated attacking ports 80 443 90 percent china people liberation army pla developed strategy called integrated network electronic warfare guides computer network operations cyberwarfare tools strategy helps link together network warfare tools electronic warfare weapons opponent information systems conflict believe fundamentals achieving success seizing control opponent information flow establishing information dominance science military science campaigns identify enemy logistics systems networks highest priority cyber-attacks states cyberwarfare must mark start campaign used properly enable overall operational success focusing attacking opponent infrastructure disrupt transmissions processes information dictate decision-making operations pla would secure cyber dominance adversary predominant techniques would utilized conflict gain upper hand follows pla would strike electronic jammers electronic deception suppression techniques interrupt transfer processes information would launch virus attacks hacking techniques sabotage information processes hopes destroying enemy information platforms facilities pla science campaigns noted one role cyberwarfare create windows opportunity forces operate without detection lowered risk counterattack exploiting enemy periods blindness deafness paralysis created cyber-attacks one main focal points cyberwarefare able weaken enemy full extent possible physical offensive higher percentage success pla conduct regular training exercises variety environments emphasizing use cyberwarfare tactics techniques countering tactics employed faculty research focusing designs rootkit usage detection kylin operating system helps train individuals cyberwarfare techniques china perceives cyberwarfare deterrent nuclear weapons possessing ability greater precision leaving fewer casualties allowing long ranged attacks west united states provides different tone voice cyberwarfare tip everyone tongue united states provides security plans strictly response cyberwarfare basically going defensive attacked devious cyber methods u.s. responsibility cybersecurity divided department homeland security federal bureau investigation department defense recent years new department created specifically tend cyber threats department known cyber command cyber command military subcommand us strategic command responsible dealing threats military cyber infrastructure cyber command service elements include army forces cyber command twenty-fourth air force fleet cyber command marine forces cyber command ensures president navigate control information systems also military options available defense nation needs enacted cyberspace individuals cyber command must pay attention state non-state actors developing cyberwarfare capabilities conducting cyber espionage cyber-attacks nation allies cyber command seeks deterrence factor dissuade potential adversaries attacking u.s. multi-faceted department conducting cyber operations three prominent events took place may catalysts creation idea cyber command failure critical infrastructure reported cia malicious activities information technology systems disrupted electrical power capabilities overseas resulted multi-city power outages across multiple regions second event exploitation global financial services november 2008 international bank compromised payment processor allowed fraudulent transactions made 130 automated teller machines 49 cities within 30-minute period last event systemic loss u.s. economic value industry 2008 estimated 1 trillion losses intellectual property data theft even though events internal catastrophes real nature meaning nothing stop state non-state actors thing even grander scale initiatives like cyber training advisory council created improve quality efficiency sufficiency training computer network defense attack exploitation enemy cyber operations ends spectrum east west nations show sword shield contrast ideals chinese offensive minded idea cyberwarfare trying get pre-emptive strike early stages conflict gain upper-hand u.s. reactionary measures taken creating systems impenetrable barriers protect nation civilians cyber-attacks according homeland preparedness news many mid-sized u.s. companies difficult time defending systems cyber attacks around 80 percent assets vulnerable cyber attack owned private companies organizations former new york state deputy secretary public safety michael balboni said private entities type capability bandwidth interest experience develop proactive cyber analysis response cyber-attacks 1 april 2015 president obama issued executive order establishing first-ever economic sanctions executive order impact individuals entities designees responsible cyber-attacks threaten national security foreign policy economic health financial stability us specifically executive order authorizes treasury department freeze designees assets according ted koppel book 2008 united states collaboration israel ran cyberattack iran nuclear program becoming first use digital weapon instrument policy series powerful cyber attacks began 27 june 2017 swamped websites ukrainian organizations including banks ministries newspapers electricity firms fifa world cup 2018 russia countered stopped around 25 million cyber attacks infrastructure june 2019 russia conceded possible electrical grid cyberattack united states new york times reported american hackers united states cyber command planted malware potentially capable disrupting russian electrical grid 2007 cyberattacks estonia series cyberattacks began 27 april 2007 targeted websites estonian organizations including estonian parliament banks ministries newspapers broadcasters amid country disagreement russia relocation bronze soldier tallinn elaborate soviet-era grave marker well war graves tallinn attacks triggered number military organizations around world reconsider importance network security modern military doctrine direct result cyberattacks creation nato cooperative cyber defence centre excellence tallinn 2019 reuters reported united arab emirates launched series cyberattacks political opponents journalists human rights activists project raven espionage platform namely karma team included ex-us intelligence agents project raven commenced 2009 planned continued coming ten years whole industry working trying minimize likelihood consequence information attack partial list see offer different products services aimed many organizations trying classify vulnerability consequence famous vulnerability database common vulnerabilities exposures computer emergency response teams set government large organization handle computer security incidents cyber-attack initiated certain targets need attacked cripple opponent certain infrastructures targets highlighted critical infrastructures time conflict severely cripple nation control systems energy resources finance telecommunications transportation water facilities seen critical infrastructure targets conflict new report industrial cybersecurity problems produced british columbia institute technology pa consulting group using data far back 1981 reportedly found 10-fold increase number successful cyber-attacks infrastructure supervisory control data acquisition scada systems since 2000 cyberattacks adverse physical effect known cyber-physical attacks control systems responsible activating monitoring industrial mechanical controls many devices integrated computer platforms control valves gates certain physical infrastructures control systems usually designed remote telemetry devices link physical devices internet access modems little security offered dealing devices enabling many hackers cyberterrorists seek systematic vulnerabilities paul blomgren manager sales engineering cybersecurity firm explained people drove remote substation saw wireless network antenna immediately plugged wireless lan cards took laptops connected system n't using passwords within 10 minutes mapped every piece equipment facility blomgren said within 15 minutes mapped every piece equipment operational control network within 20 minutes talking business network pulled several business reports never even left vehicle energy seen second infrastructure could attacked broken two categories electricity natural gas electricity also known electric grids power cities regions households powers machines mechanisms used day-to-day life using u.s. example conflict cyberterrorists access data daily report system status shows power flows throughout system pinpoint busiest sections grid shutting grids cause mass hysteria backlog confusion also able locate critical areas operation attacks direct method cyberterrorists access instructions connect bonneville power administration helps direct fault system process major advantage utilized cyber-attacks made foreign attackers prior knowledge system attack highest accuracy without drawbacks cyberattacks natural gas installations go much way would attacks electrical grids cyberterrorists shutdown installations stopping flow even reroute gas flows another section occupied one allies case russia gas supplier known gazprom lost control central switchboard routes gas flow inside operator trojan horse program bypassed security financial infrastructures could hit hard cyber-attacks financial system linked computer systems constant money exchanged institutions cyberterrorists attack transactions rerouted large amounts money stolen financial industries would collapse civilians would without jobs security operations would stall region region causing nationwide economical degradation u.s. alone average daily volume transactions hit 3 trillion 99 non-cash flow able disrupt amount money one day period days cause lasting damage making investors pull funding erode public confidence cyberattack financial institution transactions may referred cyberheist attacks may start phishing targets employees using social engineering coax information may allow attackers hack network put keyloggers accounting systems time cybercriminals able obtain password keys information organization bank accounts accessed via information stolen using keyloggers may 2013 gang carried us 40 million cyberheist bank muscat cyberattacking telecommunication infrastructures straightforward results telecommunication integration becoming common practice systems voice ip networks merging everything run internet speeds storage capabilities endless denial-of-service attacks administered previously mentioned complex attacks made bgp routing protocols dns infrastructures less likely attack would target compromise traditional telephony network ss7 switches attempted attack physical devices microwave stations satellite facilities ability would still shut physical facilities disrupt telephony networks whole idea cyber-attacks cut people one another disrupt communication impede critical information sent received cyberwarfare critical way gaining upper-hand conflict controlling flow information communication nation plan accurate strikes enact better counter-attack measures enemies transportation infrastructure mirrors telecommunication facilities impeding transportation individuals city region economy slightly degrade time successful cyber-attacks impact scheduling accessibility creating disruption economic chain carrying methods impacted making hard cargo sent one place another january 2003 slammer virus continental airlines forced shut flights due computer problems cyberterrorists target railroads disrupting switches target flight software impede airplanes target road usage impede conventional transportation methods may 2015 man chris roberts cyberconsultant revealed fbi repeatedly 2011 2014 managed hack boeing airbus flights controls via onboard entertainment system allegedly least ordered flight climb fbi detaining april 2015 syracuse interviewed allegations water infrastructure could one critical infrastructures attacked seen one greatest security hazards among computer-controlled systems potential massive amounts water unleashed area could unprotected causing loss life property damage even water supplies could attacked sewer systems compromised calculation given cost damages estimated cost replace critical water systems could hundreds billions dollars water infrastructures well developed making hard cyber-attacks cause significant damage equipment failure occur causing power outlets disrupted short time
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Computer security
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arkanoid player controls vaus space vessel acts game paddle prevents ball falling playing field attempting bounce number bricks ball striking brick causes brick disappear bricks gone player goes next level another pattern bricks appears number variations bricks hit multiple times flying enemy ships etc power-up capsules enhance vaus expand vaus multiply number balls equip laser cannon break directly next level etc gameplay remains final stage 33 versions 36 nes player takes game boss doh head resembling moai point reached player longer option continue running lives making segment difficult game regardless outcome japan gave silver award one four best games 1986 along taito bubble bobble sega fantasy zone tecmo rygar europe reviewed clare edgeley december 1986 issue computer video games compared pong space invaders simplicity addictiveness described arkanoid lovely game fast colourful simple addictive concluded great little game also commercially successful arcades game appeared number-three euromax nationwide uk arcade chart 1987 capcom 1942 number-one westone wonder boy number-two home versions also well received computer gaming world stated 1988 arkanoid amiga perfect version arcade game ... incredible named nes version best arcade translation console year praising graphics play mechanics game reviewed 1989 dragon 144 hartley patricia kirk lesser role computers column reviewers gave game 5 5 stars compute named game list nine great games 1989 describing hypnotic addictive fascinating along breakout magazine noted arkanoid also elements pong space invaders well pac-man use power-ups arkanoid ported zx spectrum amstrad cpc commodore 64 bbc micro msx atari 8-bit family apple ii nes amiga atari st apple ii ibm pc macintosh version released 1987 port released tandy color computer 3 1989 computer conversions published imagine nes port packaged custom controller arkanoid followed number direct indirect sequels tournament arkanoid released 1987 exclusively united states romstar unlike original game developed taito america rather taito japan mission-pack sequel true sequel since exact gameplay original arkanoid levels different. arkanoid 2 released arcades 1987 unlike tournament arkanoid revenge doh true sequel game featuring new gameplay mechanics. arkanoid returns published 1997 followed arkanoid ds 2007 xbox 360 version arkanoid titled arkanoid live released may 6 2009 xbox live arcade wiiware version arkanoid titled arkanoid plus released japan may 26 2009 pal regions august 21 2009 north america september 28 2009 version arkanoid iphone released worldwide august 31 2009 mashup arkanoid vs. space invaders released 2017 ios android arkanoid world-record score belongs zack hample known snagged 10,000 baseballs major league baseball games
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Computer architecture
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g.hn g.hn specification home networking data rates 2 gbit/s operation four types legacy wires telephone wiring coaxial cables power lines plastic optical fiber single g.hn semiconductor device able network supported home wire types benefits multi-wire standard lower equipment development costs lower deployment costs service providers allowing customer self-install g.hn developed international telecommunication union telecommunication standardization sector itu-t promoted homegrid forum several organizations itu-t recommendation itu term standard g.9960 received approval october 9 2009 specified physical layers architecture g.hn data link layer recommendation g.9961 approved june 11 2010 key promoters cepca homepna upa creators two interfaces united behind latest version standard february 2009 itu-t extended technology multiple input multiple output mimo technology increase data rates signaling distance new feature approved march 2012 g.9963 recommendation amendments main g.9960/g.9961 added new functionalities base standard g.hn specifies single physical layer based fast fourier transform fft orthogonal frequency-division multiplexing ofdm modulation low-density parity-check code ldpc forward error correction fec code g.hn includes capability notch specific frequency bands avoid interference amateur radio bands licensed radio services g.hn includes mechanisms avoid interference legacy home networking technologies also wireline systems vdsl2 types dsl used access home ofdm systems split transmitted signal multiple orthogonal sub-carriers g.hn one sub-carriers modulated using qam maximum qam constellation supported g.hn 4096-qam 12-bit qam g.hn media access control based time division multiple access tdma architecture domain master schedules transmission opportunities txops used one devices domain two types txops although elements g.hn common three media supported standard power lines phone lines coaxial cable g.hn includes media-specific optimizations media media-specific parameters include g.hn uses advanced encryption standard aes encryption algorithm 128-bit key length using ccmp protocol ensure confidentiality message integrity authentication key exchange done following itu-t recommendation x.1035 g.hn specifies point-to-point security inside domain means pair transmitter receiver uses unique encryption key shared devices domain example node alice sends data node bob node eve domain alice bob able easily eavesdrop communication g.hn supports concept relays one device receive message one node deliver another node farther away domain relaying becomes critical applications complex network topologies need cover large distances found industrial utility applications relay read source target addresses read message content due body end-to-end-encrypted g.hn architecture includes concept profiles profiles intended address g.hn nodes significantly different levels complexity g.hn higher complexity profiles proper supersets lower complexity profiles devices based different profiles interoperate examples g.hn devices based high complexity profiles residential gateways set-top boxes examples g.hn devices based low complexity profiles home automation home security smart grid devices g.hn spectrum depends medium shown diagram g.hn specifies physical layer data link layer according osi model pmd sub-layer sub-layer g.hn stack medium dependent i.e. parameters may different values media power lines phone lines coaxial cable rest sub-layers apc llc mac pcs pma medium independent interface application entity data link layer called a-interface interface data link layer physical layer called medium independent interface mii interface physical layer actual transmission medium called medium dependent interface mdi recommendation g.9960 granted approval october 2009 study group 15 plenary meeting recommendation g.9961 received approval june 11 2010 meeting concerns regulatory conformance raised amendment g.hn standard proposed eliminated passband 100 mhz 200 mhz reduced baseband operational spectrum 100 mhz 80 mhz changes included amendment included reduction transmit power meet regulatory complaints raised meeting june 2011 joint forum held itu-t itu-r organizations recognized itu-t g.hn considered electromagnetic compatibility emc mitigation techniques go well beyond considered essential protecting radio services non-itu compliant home network equipment may cause problems october 2010 sigma designs announced first g.hn-compliant chipset called cg5110 january 2011 lantiq introduced family g.hn-compliant chips called hnx176 hnx156 june 2011 four silicon vendors lantiq marvell semiconductor metanoia sigma designs announced participation open interoperability plugfest geneva hosted homegrid forum broadband forum itu homegrid forum showcased world first live public demonstration g.hn interoperability ces january 10–13 2012 homegrid forum members lantiq marvell metanoia sigma designs joined together highlight real-world g.hn capabilities january 2012 tangotec ltd. announced fully compliant itu-t g.hn chipset family available 2012 tangotec demonstrated g.hn capabilities three media ces 2012 december 2012 marvell homegrid forum announced marvell g.hn silicon passed compliance tests first compliance certified g.hn silicon first certified g.hn silicon interop testing remains homegrid forum non-profit trade group promoting g.hn homegrid forum provides technical marketing efforts addresses certification interoperability g.hn-compliant products cooperates complementary industry alliances homegrid forum members include actiontec electronics inc. allion test labs inc. arris bc institute technology best buy british telecom bt chunghwa telecom comtrend corporation holland electronics llc institute information industry iii korea electrotechnology research institute keri korea polytechnic university kpu kwangwoon university lan s.a.r.l marvell metanoia communications inc. mitrastar sigma designs teleconnect gmbh telefónica university british columbia trac global xingtera inc vendors promoting g.hn include maxlinear lantiq devolo ag microprocessor manufacturer intel system-on-a-chip vendor sigma designs xingtera announced product january 2013 first live public demonstration g.hn interoperability shown ces january 10–13 2012 lantiq marvell technology group metanoia sigma designs february 26 2009 part homepna press release makes use wireline home networking part u-verse iptv service expressed support work developed itu-t creating standards home networking including g.hn service providers like promoted g.hn service providers contributors work itu-t study group include british telecom telefónica april 2008 first announcement homegrid forum echostar manufacturer set-top boxes service provider market expressed support unified standard march 2009 best buy largest retailer consumer electronics united states joined board directors homegrid forum expressed support g.hn panasonic one largest manufacturers consumer electronics also contributor member homegrid forum 2008 several marketing firms promoted g.hn made optimistic predictions february 25 2009 three home networking organizations promoted previously incompatible technologies cepca homepna universal powerline association announced agreed work homegrid forum promote g.hn single next-generation standard wired home networking work ensure coexistence existing products market october 2008 continental automated buildings association caba homegrid forum signed liaison agreement support homegrid forum efforts conjunction itu-t g.hn make easy consumers connect devices enjoy innovative applications using existing home wiring july 2009 homegrid forum dlna signed liaison agreement setting stage collaboration two organizations approval g.hn dlna-recognized physical layer technology june 2010 broadband forum homegrid forum signed agreement deliver compliance interoperability testing program products using g.hn technology broadband forum support homegrid forum validation g.hn products promotion product conformance interoperability help expedite total time market homegrid forum certified products may 2011 organizations jointly announced first open g.hn plugfest itu g.9970 also known g.hnta recommendation developed itu-t describes generic architecture home networks interfaces operators broadband access networks itu g.9972 also known g.cx recommendation developed itu-t specifies coexistence mechanism home networking transceivers capable operating power line wiring coexistence mechanism would allow g.hn devices implement g.9972 coexist devices implementing g.9972 operating power line wiring itu g.9991 also known g.vlc recommendation developed itu-t specifies phy dll high speed indoor visible light communication transceivers used applications li-fi g.vlc reuses phy dll g.hn enabling chips used applications major motivation wired home networking technologies iptv especially offered service provider part triple play service voice data service offering u-verse smart grid applications like home automation demand side management also targeted g.hn-compliant devices implement low-complexity profiles many customers homes residential gateway provides internet access located close iptv set-top box scenario becomes common service providers start offer service packages multiple set-top boxes per subscriber g.hn connect residential gateway one set-top boxes using existing home wiring using g.hn iptv service providers need install new ethernet wires 802.11 wireless networks g.hn supports kind home wiring end users might install iptv home network thus reducing cost service provider although wi-fi technology popular consumer home networks g.hn also intended use application g.hn adequate solution consumers situations using wireless needed example connect stationary device like tv network-attached storage device desired due security concerns feasible example due limited range wireless signals consumer electronics ce products support internet connectivity using technologies wi-fi bluetooth ethernet many products traditionally associated computer use tvs hi-fi equipment provide options connect internet computer using home network provide access digital content g.hn intended provide high-speed connectivity ce products capable displaying high definition television integrating power connection data connection provides potential energy savings ce devices given ce devices home theater receivers often run standby vampire power represent major savings homeowners power connection also data connection device could reliably turned displaying source g.hn operate wires including ac dc power lines provide communication infrastructure required smart grid applications comprehensive smart grid system requires reaching every ac outlet home building devices participate energy conserving strategies september 2009 us national institute standards technology included g.hn one standards smart grid believed strong stakeholder consensus part early draft nist framework roadmap smart grid interoperability standards january 2010 g.hn removed final version standards identified implementation broad concept smart grid includes applications overlapping scopes demand side management energy conservation measures advanced metering infrastructure ami home networks g.hn supports popular protocols like ipv4 ipv6 g.hn-based networks easily integrated ip-based networks well-known network management protocols like simple network management protocol snmp manage ip networks including g.hn devices
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Internet protocols
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tcp window scale option tcp window scale option option increase receive window size allowed transmission control protocol former maximum value 65,535 bytes tcp option along several others defined ietf rfc 1323 deals long fat networks lfns throughput communication limited two windows congestion window receive window congestion window tries exceed capacity network congestion control receive window tries exceed capacity receiver process data flow control receiver may overwhelmed data example busy web server tcp segment contains current value receive window example sender receives ack acknowledges byte 4000 specifies receive window 10000 bytes sender send packets byte 14000 even congestion window allows tcp window scale option needed efficient transfer data bandwidth-delay product bdp greater 64k instance t1 transmission line 1.5 mbit/second used satellite link 513 millisecond round trip time rtt bandwidth-delay product formula_1 bits 96,187 bytes using maximum buffer size 64 kib allows buffer filled 65,535 96,187 68 theoretical maximum speed 1.5 mbits/second 1.02 mbit/s example receive window formula_2 bytes receive window 2 bytes tcp header window scale factor options tcp 3 calculation follows formula_3 bytes essence formula_4 shifting 3 bits left note options field window scale factor sent syn packet also value window scale factor go 255 formula_5 byte maximum allowed 14 reason maximum value 14 formula_6 increases beyond surpass sequence sequence 4 bytes formula_7 size window ca n't go beyond maximum value sequence using window scale option receive window size may increased maximum value 1,073,725,440 bytes done specifying one byte shift count header options field true receive window size left shifted value shift count maximum value 14 may used shift count value would allow single tcp connection transfer data example satellite link 1.5 mbit/second utilizing available bandwidth essentially one full transmission window transferred within one round-trip time period window scale option enables single tcp connection fully utilize lfn bdp 1 gb e.g 10 gbit/s link round-trip time 800 ms. firewalls properly implement tcp window scaling cause user internet connection malfunction intermittently minutes appear start working reason also issue firewall n't support tcp extensions tcp window scaling implemented windows since windows 2000 enabled default windows vista server 2008 newer turned manually required windows vista windows 7 fixed default tcp receive buffer 64 kb scaling 16 mb autotuning limiting manual tcp tuning long fat networks linux kernels 2.6.8 august 2004 enabled tcp window scaling default configuration parameters found /proc filesystem see pseudo-file companions information section sysctl scaling turned issuing command root maintain changes restart include line systemd 207 default setting freebsd openbsd netbsd mac os x window scaling features related rfc 1323 enabled verify status user check value variable via sysctl command value 1 output means scaling enabled 0 means disabled enabled turned issuing command setting lost across system restart ensure set boot time add following line /etc/sysctl.conf codice_1
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Internet protocols
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brian jacks superstar challenge brian jacks superstar challenge 1985 sports simulation game released various home computers martech licensed british sportsman brian jacks released systems including commodore 64 bbc micro acorn electron electron user praised superb graphics variety found different games
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Computer architecture
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whitesource whitesource open source security license compliance management platform founded 2011 ron rymon azi cohen rami sass company founded three co-founders sold previous company eurekify ca technologies due diligence process co-founders experienced first hand challenge generating accurate open source inventory report company launched open source license management platform software discovers open source components customers ’ apps alerts vulnerable code added software projects used threats pop affect existing software main investors company include susquehanna growth equity 83north microsoft ventures david strohm israeli innovation authority company raised 46 million 2018 whitesource bolt launched 2016
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Computer security
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x86 virtualization article documents hardware capabilities cpus implementing x86 x86-64 instruction sets regards hardware-assisted virtualization late 1990s x86 virtualization achieved complex software techniques necessary compensate processor lack hardware-assisted virtualization capabilities attaining reasonable performance 2006 intel vt-x amd amd-v introduced limited hardware virtualization support allowed simpler virtualization software offered speed benefits greater hardware support allowed substantial speed improvements came later processor models following discussion focuses virtualization x86 architecture protected mode protected mode operating system kernel runs higher privilege ring 0 applications lower privilege ring 3 software-based virtualization host os direct access hardware guest oss limited access hardware like application host os one approach used x86 software-based virtualization overcome limitation called ring deprivileging involves running guest os ring higher lesser privileged 0 three techniques made virtualization protected mode possible techniques incur performance overhead due lack mmu virtualization support compared vm running natively virtualizable architecture ibm system/370 traditional mainframes classic type 1 hypervisor self-standing depend operating system run user applications contrast first x86 virtualization products aimed workstation computers ran guest os inside host os embedding hypervisor kernel module ran host os type 2 hypervisor controversy whether x86 architecture hardware assistance virtualizable described popek goldberg vmware researchers pointed 2006 asplos paper techniques made x86 platform virtualizable sense meeting three criteria popek goldberg albeit classic trap-and-emulate technique different route taken systems like denali l4 xen known paravirtualization involves porting operating systems run resulting virtual machine implement parts actual x86 instruction set hard virtualize paravirtualized i/o significant performance benefits demonstrated original sosp'03 xen paper initial version x86-64 amd64 allow software-only full virtualization due lack segmentation support long mode made protection hypervisor memory impossible particular protection trap handler runs guest kernel address space revision later 64-bit amd processors rule thumb manufactured 90 nm less added basic support segmentation long mode making possible run 64-bit guests 64-bit hosts via binary translation intel add segmentation support x86-64 implementation intel 64 making 64-bit software-only virtualization impossible intel cpus intel vt-x support makes 64-bit hardware assisted virtualization possible intel platform platforms possible run 64-bit guest 32-bit host os underlying processor 64-bit supports necessary virtualization extensions 2005 2006 intel amd working independently created new processor extensions x86 architecture first generation x86 hardware virtualization addressed issue privileged instructions issue low performance virtualized system memory addressed mmu virtualization added chipset later based painful experiences 80286 protected mode suitable enough run concurrent ms-dos applications well intel introduced virtual 8086 mode 80386 chip offered virtualized 8086 processors 386 later chips hardware support virtualizing protected mode however became available 20 years later amd developed first generation virtualization extensions code name pacifica initially published amd secure virtual machine svm later marketed trademark amd virtualization abbreviated amd-v may 23 2006 amd released athlon 64 orleans athlon 64 x2 windsor athlon 64 fx windsor first amd processors support technology amd-v capability also features athlon 64 athlon 64 x2 family processors revisions f g socket am2 turion 64 x2 opteron 2nd generation third-generation phenom phenom ii processors apu fusion processors support amd-v. amd-v supported socket 939 processors sempron processors support huron sargas amd opteron cpus beginning family 0x10 barcelona line phenom ii cpus support second generation hardware virtualization technology called rapid virtualization indexing formerly known nested page tables development later adopted intel extended page tables ept cpu flag amd-v svm may checked bsd derivatives via dmesg sysctl linux via codice_1 previously codenamed vanderpool vt-x represents intel technology virtualization x86 platform november 13 2005 intel released two models pentium 4 model 662 672 first intel processors support vt-x cpu flag vt-x capability vmx linux checked via codice_1 macos via codice_3 vmx stands virtual machine extensions adds ten new instructions vmptrld vmptrst vmclear vmread vmwrite vmcall vmlaunch vmresume vmxoff vmxon instructions permit entering exiting virtual execution mode guest os perceives running full privilege ring 0 host os remains protected almost newer server desktop mobile intel processors support vt-x intel atom processors primary exception motherboards users must enable intel vt-x feature bios setup applications make use intel started include extended page tables ept technology page-table virtualization since nehalem architecture released 2008 2010 westmere added support launching logical processor directly real mode feature called unrestricted guest requires ept work since haswell microarchitecture announced 2013 intel started include vmcs shadowing technology accelerates nested virtualization vmms virtual machine control structure vmcs data structure memory exists exactly per vm managed vmm every change execution context different vms vmcs restored current vm defining state vm virtual processor soon one vmm nested vmms used problem appears way similar required shadow page table management invented described cases vmcs needs shadowed multiple times case nesting partially implemented software case hardware support processor make shadow vmcs handling efficient intel implemented hardware support vmcs shadowing via nano 3000 series processors higher support via vt virtualization technology compatible intel vt 2012 amd announced advanced virtual interrupt controller avic targeting interrupt overhead reduction virtualization environments technology announced support x2apic 2016 avic available amd family 15h models 6xh carrizo processors newer also 2012 intel announced similar technology interrupt apic virtualization brand name announcement time later branded apic virtualization apicv became commercially available ivy bridge ep series intel cpus sold xeon e5-26xx v2 launched late 2013 xeon e5-46xx v2 launched early 2014 graphics virtualization technology introduced intel iris pro intel integrated gpu either dedicatedly assigned virtual machine gvt-d shared multiple virtual machines time-sharing basis using native graphics driver gvt-g shared multiple virtual machines using virtual graphics driver gvt-s memory i/o virtualization performed chipset typically features must enabled bios must able support also set use input/output memory management unit iommu allows guest virtual machines directly use peripheral devices ethernet accelerated graphics cards hard-drive controllers dma interrupt remapping sometimes called pci passthrough iommu also allows operating systems eliminate bounce buffers needed allow communicate peripheral devices whose memory address spaces smaller operating system memory address space using memory address translation time iommu also allows operating systems hypervisors prevent buggy malicious hardware compromising memory security amd intel released iommu specifications addition cpu support motherboard chipset system firmware bios uefi need fully support iommu i/o virtualization functionality usable pci pci express devices supporting function level reset flr virtualized way required reassigning various device functions virtual machines device assigned support message signaled interrupts msi must share interrupt lines devices assignment possible conventional pci devices routed behind pci/pci-x-to-pci express bridge assigned guest virtual machine pci express devices restriction pci-sig single root i/o virtualization sr-iov provides set general non-x86 specific i/o virtualization methods based pci express pcie native hardware standardized pci-sig sr-iov common host vmm configures supported devices create allocate virtual shadows configuration spaces virtual machine guests directly configure access shadow device resources sr-iov enabled virtualized network interfaces directly accessible guests avoiding involvement vmm resulting high overall performance example sr-iov achieves 95 bare metal network bandwidth nasa virtualized datacenter amazon public cloud
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Computer architecture
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clustrix clustrix inc. san francisco-based private company founded 2006 develops database management system marketed newsql clustrix founded november 2006 sometimes called sprout-clustrix formed help combinator founders include paul mikesell formerly emc isilon sergei tsarev technology tested customers since 2008 initially called sierra official announcement 2010 product called clustered database system cds company received 10 million funding sequoia capital u.s. venture partners usvp ata ventures december 2010 robin purohit became chief executive october 2011 another round 6.75 million raised july 2012 another round funding original backers 16.5 million announced may 2013 round 10 million new funding august 2013 led highbar ventures purohit replaced mike azevedo 2014 round 23 million debt financing disclosed february 2016.. september 20 2018 announced clustrix acquired mariadb corporation clustrix supports workloads involve scaling transactions real-time analytics system drop-in replacement mysql designed overcome mysql scalability issues minimum disruption also built fault-tolerance features high availability within cluster parallel backup parallel replication among clusters disaster recovery clustrix scale-out sql database management system part often called newsql database systems modern relational database management systems closely following nosql movement product marketed hardware appliance using infiniband 2014 clustrix database made available downloadable software amazon web services marketplace 2013 primary competitors like microsoft sql server mysql supported online transaction processing online analytical processing distributed clustrix provides distributed relational acid database scales transactions support real-time analytics distributed relational databases columnar n't support primary transaction workload focus offline analytics includes emc greenplum hp vertica infobright amazon redshift notable players primary sql database space in-memory includes voltdb memsql excel low-latency transactions target real-time analytics nosql competitors like mongodb good handling unstructured data read heavy workloads compete space write heavy workloads transactions coarse grained db-level locking sql features like joins newsql nosql databases complementary clustrix database operates distributed cluster shared-nothing nodes using query data approach nodes typically subset data sql queries split query fragments sent nodes data enables clustrix scale horizontally scale additional nodes added clustrix database automatically splits distributes data evenly across nodes slice copies nodes uniform data distribution maintained nodes added removed data inserted unevenly automatic data distribution approach removes need shard enables clustrix maintain database availability face node loss performance test completed percona 2011 three-node cluster saw 73 increase speed similarly equipped single mysql server running tests 1024 simultaneous threads additional nodes added clustrix cluster provided roughly linear increases speed
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Databases
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openwebglobe openwebglobe project technology processing interactively visualizing vast volumes geospatial data 3d virtual globe openwebglobe virtual globe several data categories like image data elevation data points interest vector data 3d objects streaming massive complex data internet data must pre-processed pre-processing usually comprises transformation local global reference system creation pyramid layers levels detail lod tiling data optionally compression encryption recently algorithms ported high performance compute cluster using openmp mpi also released open-source data sets usually large containing several terabytes advanced out-of-core rendering mechanisms level detail approach used visualization openwebglobe open-source project written webgl lead developer institute geomatics engineering university applied sciences northwestern switzerland openwebglobe sdk also 3d engine top webgl openwebglobe sdk possible create custom virtual globe applications javascript hello world example creates virtual globe adds image elevation layer demo version potential 3d viewer codice_1 geo-portal swiss confederation online openwebglobe website july 31 2012 scene covered entire switzerland based high resolution data swisstopo swissimage
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Programming language topics
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l'empereur user controls napoleon bonaparte napoleonic wars late 18th early 19th centuries goal conquer europe game begins napoleon army officer victories combat user may get promoted commander-in-chief first consul finally emperor french powers actions available level emperor user also controls napoleon brothers louis jérôme lucien joseph well napoleon stepson eugene beauharnais game military civilian aspects user lead armies act mayor cities depending level achieved engage diplomacy nations historically accurate game reproduces many historical figures militaries europe great detail player chooses one four scenarios loads saved game starts different years earliest scenario napoleon commander marseille 1796 historically poised invasion italy second scenario napoleon st. malo commander-in-chief 1798 third scenario arguably easiest starting point napoleon first consul france 1802 final scenario napoleon emperor starts 1806 mode player control napoleon siblings stepson well turn lasts one full month per year total 12 turns per year although years change every january march gameplay elements affected game engine drafting soldiers officers termination certain diplomatic agreements collection taxes month player well commanders cities manage military civil affairs respective cities additionally every three months starting march national leaders may carry diplomatic national affairs crux gameplay rests actual battles take place special tiled battlefields arranged hexes opposing commanders place armies accordingly maneuver around battlefield battle defenders responsibility keeping city hexes control repelling enemy attackers either take city hexes annihilate defenders run food forced retreat number terrain features add depth gameplay swamps forests hills mountains rivers tundra also seasons weather affect battle invasions winter months causing bodies water freeze generally slowing movement troops troops frozen water fall bombarded happened battle austerlitz army may consist three types units basic infantry build explode bridges cavalry charge enemy allowing repeatedly attack unit single turn artillery bombard enemies afar unit three main factors determining well fight strength go 200 soldiers per unit training affects accurate unit attacks speed unit moves morale determines well unit absorbing attacks avoiding falling crippling disorder additionally unit commanding officer ratings leadership experience commanding unit type infantry cavalry artillery affects unit attack/defense power morale napoleon player basic goal conquer europe many players could daunting task time sheer size task require patient planning careful strategizing accomplish scenario presents easier goal achieve basically napoleon promoted commander c-in-c first consul emperor l'empereur features large number historical figures including emperor alexander russia king george iii britain duke wellington marshal kutusov russia general blücher prussia archduke charles austria many french generals masséna macdonald davout soult lannes oudinot berthier also appear give significant advantage france political figures also make appearances talleyrand godoy metternich game models several nations republican imperial france including kingdom naples republic venice prussia britain holland bavaria spain portugal ottoman empire turkey austria denmark sweden russia historical events portrayed napoleon invasion egypt divorce josephine marriage marie louise napoleon overthrowing barras also portrayed although events napoleon overthrow peacefully also modeled russian cossacks spanish guerrillas greatly complicating invasions respective countries plague also appear disaster game permits recreation battle trafalgar occurs whenever napoleon attempts invade england gibraltar sea nelson killed england gets free naval victory france french naval force small english automatically win combat lord nelson die computer gaming world disliked game historical inaccuracies describing disappointing seeking computer version empires arms miniature wargame 1993 survey pre 20th-century strategy games magazine gave game one-plus stars five stating little ambience napoleonic era including unrealistic artillery ranges
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Computer architecture
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ensoniq audiopci ensoniq audiopci pci-based sound card released 1997 ensoniq last sound card product acquired creative technology card represented shift ensoniq market positioning whereas soundscape line made primarily low-volume high-end products full features audiopci designed simple low-cost product appeal system oems thus hopefully sell mass quantities towards end 1990s ensoniq struggling financially cards popular pc oems costs high musical instrument division fading revenue pressure intense competition especially dominant creative labs forcing audio card makers try keep prices low audiopci released july 1997 designed primarily cheap comparison wide variety chips sheer size older soundscape boards highly integrated two chip design audiopci obvious shift design philosophy board consists small software-driven audio chip one following s5016 es1370 es 1371 companion digital-to-analog converter dac another cost-cutting move previously typical rom chip used storage samples sample-based synthesis replaced facility use system ram storage audio data made possible move pci bus far greater bandwidth efficient bus mastering interface compared older isa bus standard audiopci designed cheap still quite functional offers many audio capabilities soundscape elite card surpasses soundscape cards notably audiopci supports several digital effects reverb chorus spatial enhancement used microsoft windows 95 later versions windows audiopci surprises market one first cards microsoft directsound3d 4-speaker playback support 4-speaker mode activated software supporting directsound3d quadraphonic mode oddity rear channel connected output jack line input jack switches modes 4-speaker output became active dos windows drivers support sample-based synthesis ensoniq .ecw patch set format several patch set choices available varying size instrument quality 2 4 8 mb .ecw file format ensoniq concert wavetable never made open hoped enthusiasts consequently custom wave sets available contrast huge availability home-made releases e-mu soundfont format particularly unfortunate audiopci used system ram patch set storage offers tremendous potential new patch sets traditional rom storage previously used also disappointing considering incredible popularity longevity ensoniq es1370 chipset descendants still use six years original audiopci board fact dos drivers far newer sound blaster audigy still use .ecw wave sets newer cards unable use soundfonts dos limiting three official .ecw wavesets late '90s one incomplete unofficial waveset audiopci supported dos games applications using software driver would install dos real-mode boot-time portion windows 9x driver virtualized sound blaster-compatible isa sound card use pc nmi tsr program allowed audiopci compatible out-of-the-box dos support pci competitors time example competing monster sound diamond multimedia limited running dos games windows 9x-based dos command windows meaning dos compatibility frequently reliable additional isa sound card creative struggling challenge legacy support well created sb-link interconnect allowed access serial-irq pc/pci grant/request sideband signals offered pci chipsets time order achieve dos compatibility sound blaster awe64-variant pci sound cards sb-link also used number chipset vendors ess yamaha ensoniq approach generally worked games older games problems detecting virtualized hardware systems addition dos driver required memory manager emm386 loaded required additional conventional memory space also put cpu virtual-86 mode conflicting games utilized modified form protected mode called 'flat mode mode allowed fast direct access system entire ram without requiring memory manager memory protection mechanism requirement exclusive audiopci however number isa sound cards used well including creative awe isa series audiopci dos driver included ensoniq soundscape 16-bit digital audio sample-based synthesis support along support sound blaster pro adlib gold general midi mt-32 however without actual hardware fm synthesis fm music sound effects simulated using samples often unacceptable results therefore practical configure dos games utilize general midi synthesizer digital sound effects whenever possible better sound quality dos midi utilizes .ecw patch set files windows midi part deal ensoniq purchased creative labs integrate audiopci dos driver upcoming sound blaster live creative added sound blaster 16 emulation driver removed ensoniq soundscape support audiopci re-branded several creative labs sound cards including sound blaster pci 64 pci 128 vibra pci others ensoniq es1370 audio chip renamed creative 5507 revised ac'97-compliant variants es1371 es1373 used several years card integrated motherboard audio cards es1370 run natively 44 khz sampling frequency meaning 12 24 32 48 khz become resampled resampling means lower sound quality worse synchronization possibly higher cpu utilization cards es1371 run 48 khz conforming ac97 11 22 44 khz become resampled soundcards feature multiple quartzes pll resampling often used potential problems creative labs malvern former ensoniq company acquired later released ectiva 1938 ev1938 single chip pci audio controller based es1371/es1373 register compatible previous chips main difference ev1938 previous chips inclusion built-in ac'97 codec hence producing cheaper single chip audio solution ev1938 also used integrated audio laptops/motherboards cards sound blaster audiopci 64v ct4730 audiopci es1370 developed ensoniq one important feature chip used pci bus instead isa bus commonly used sound cards point one first pci sound card solutions offer ms-dos legacy compatibility without special hardware extensions standard pci slot paired capable codec ak4531 pre-ac'97 es1370 supported then-latest 3d audio positioning 4-speaker surround sound chip also pci bus master device designed provide high-speed access system ram resources sample synthesis data effect processing depending drivers may also called sound blaster 64/128 device manager es1370 one first audio chips support microsoft directsound3d audio api programs took full advantage api capabilities es1370 capable global spatial localized 3d sound effects 2 4-speaker mode chip capable spatializing audio automatically still required directsound3d usage specific localization sounds es1370 also emulated piece virtual hardware qemu vmware ensoniq/creative es1371 es1373 audiopci 97 ac'97-compatible versions https //downloadcenter.intel.com/detail_desc.aspx lang=eng changelang=true dwnldid=2583 ct5880 chip relabeled es1371 may found cheap cards i.e sb creative vibra 128 pci creative ev1938 audiopci 64v virtually identical es1371/es1373 later cost reduced product
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Computer architecture
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personyze personyze web 2.0 start-up company based tel aviv israel provides software service saas website personalization personyze founded november 2008 tel aviv israel yakov shabat danny hen within two years became leading personalization website providers facebook integration behavioral targeting personyze also provides analytics a/b testing june 2011 rapleaf announced partnership personyze allow use demographics database july 2011 introduced plugins content management systems wordpress joomla personyze criticized forbes contributing filter bubble technology sorts everything basis user activities may consequently present visitors portion content/offers excluding content/offers ever presented russian website- http //www.personyze.ru
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Web technology
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sendo x2 sendo x2 second series 60 mobile phone developed sendo announced smallest lightest series 60 mobile marketplace sendo x2 first music mobile announced good six months sony ericsson announced w800 walkman phone although phone announced shown 3gsm world congress cannes february 2005 x2 never made production sendo went administration matter weeks x2 due released led uk based mobile phone magazines publishing reviews phone knew sendo codename x2 development tobi
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Operating systems
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odbc administrator odbc administrator 32-bit utility mac os x operating system administering odbc enables interaction odbc-compliant data sources features include connection pooling trace log creation odbc driver management among administration features although apple started including underlying iodbc libraries mac os x jaguar 10.2.x continued least macos high sierra 10.13.x apple included odbc administrator mac os x leopard 10.5.x temporarily made available separate download since removed mac os x snow leopard 10.6.x alternatives apple 32-bit odbc administrator include free open source 32-bit 64-bit iodbc administrator included iodbc sdk available extant versions mac os x 10.0.x 10.13.x
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Operating systems
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doublepulsar doublepulsar backdoor implant tool developed u.s. national security agency nsa equation group leaked shadow brokers early 2017 tool infected 200,000 microsoft windows computers weeks used alongside eternalblue may 2017 wannacry ransomware attack variant doublepulsar first seen wild march 2016 discovered symantec sean dillon senior analyst security company risksense inc. first dissected inspected doublepulsar said nsa exploits 10 times worse heartbleed security bug use doublepulsar primary payload doublepulsar runs kernel mode grants cybercriminals high level control computer system installed uses three commands ping kill exec latter used load malware onto system
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Computer security
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windows live windows live discontinued brand-name set web services software products microsoft part software plus services platform chief components brand name included web services exposed corresponding web apps several computer programs interact services specialized web services mobile devices according microsoft windows live way extend windows user experience windows vista welcome screen provides link download windows live messenger subscribe windows live onecare also windows mail windows photo gallery windows movie maker offered windows 7 became exclusive part windows live microsoft announced windows 8 would see windows live apps included right out-of-the-box would include built-in synchronization technologies powered onedrive skydrive windows live brand phased august 2012 microsoft released windows 8 manufacturing active windows live services remained active gradually renamed live domain however continues used urls many online microsoft sites addition windows live mainly aimed individuals microsoft brands properties live including windows live first announced november 1 2005 initial release several windows live properties rebranded enhanced microsoft msn set products services however msn still exists alongside windows live means delivering content opposed customized content communications may 2012 microsoft began renaming windows live services partly anticipation windows 8 integrates many windows live products services operating system following services part windows live still online services still use live branding url even though brand name dropped windows phone free online companion service windows phone mobile devices provides users free mobile phone back-up solution wirelessly synchronizing contacts calendar appointments photos onenote notebooks password-protected online portal users access manage information stored windows phone devices via online portal using microsoft account well accessing set features remotely ringing locking mapping erasing lost phones service integrates tightly windows live services including people calendar skydrive microsoft released windows live messenger application ios app store allows users mobile devices running ios communicate contacts via microsoft messenger service addition instant messaging functionalities application also allows users view messenger social feed view friends profile integrate hotmail photos windows live also provides customised services specifically created feature phones offered via three channels — client-based windows mobile supported mobile devices nokia phones web-based wap gprs-enabled mobile web browsers sms-based services bing replacement search engine live search originally named windows live search msn search prior part windows live family services windows live search occupied homepage live.com domain windows live services however march 21 2007 microsoft decided separate search developments windows live services family forming part live search ad platform part reorganization new search brand live search consolidated microsoft adcenter part microsoft platform systems division however microsoft recognised brand issue word live continued remain brand effort create new identity microsoft search services june 3 2009 live search officially rebranded bing live connect collection apis common controls allow developers deeper control offers access core windows live services data open easily accessible application programming interfaces apis live connect built standard web technologies oauth 2.0 representational state transfer rest javascript object notation json designed work technology device live connect unites previously separate apis windows live single api based industry standards specifications microsoft released several computer programs windows live brand summary included except windows live onecare freeware published software suite called windows essentials formerly windows live essentials essentials programs designed integrate well within windows windows live services onedrive outlook.com windows live onecare hand commercial consumers utility marketed software service licensing model windows live butterfly awards program formerly msn butterfly program program whose members given benefit new microsoft software test beta releases went public direct contact program managers windows live products microsoft initiated windows live butterfly program order recognize contributions made exemplary beta testers prospective 'butterflies selected windows live product team nominated term one year could renominated windows live butterfly program closed june 2009 windows live websites sport common theme different themes used sites phase product release called waves wave set online services desktop programs windows essentials web services labelled wave example hotmail wave 4 programs windows essentials usually called year number example windows live messenger 2011 original windows live applications services used visual theme known blue vapor flair theme longer exists current windows live properties public beta release windows live wave 2 suite wave refers group wave products released new visual theme released enable aero transparency effect windows vista theme longer exists current windows live properties microsoft released set new themes windows live wave 3 services allows users customize pages windows live using set pre-selected background pictures several themes dynamic change according time day current weather condition user theme remains use sites windows live admin center addition themes provided windows live wave 3 release windows live wave 4 provided additional themes users customise pages windows live several dynamic themes changes according time day weather conditions user location several newly added themes similar wallpapers originating windows 7 addition windows live wave 4 header features reorganised dynamic navigation menu displays number user current online contacts number unread e-mails well in-built windows live web messenger service allowing users connect microsoft messenger service facebook chat service chat online contacts browsing windows live properties using web browser theme remains use sites family safety windows live apps windows 8 designed metro-style user interface web services also feature new metro-style user interface stop using windows live names ui header contains pull-down element allow users easily switch outlook.com people calendar onedrive header color also changes depending web service user using exception outlook.com allow users customize header color according preference new interface also in-built messaging sidebar allow users view presence instant message audio call video call contacts messenger facebook chat well skype february 2014 wave 5 services office web apps consolidated rebranded office online windows live services renamed listed
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Web technology
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superman man steel 1989 video game superman man steel 1989 video game based dc comics flagship character superman developed published uk software company tynesoft license first star software game split distinct levels including 3d flying overhead vertical scrolling side scrolling sections sections different almost like different games number sections depended format e.g part seven missing versions sections linked comic book graphics telling story first level pseudo-3d forward scrolling flying level similar space harrier superman en route metropolis s.t.a.r labs attacked darkseid para-demons part two set ship lois lane held hostage terrorists takes form side scrolling fighting game superman fighting terrorists reach free lois third part overhead view vertical scrolling section set space superman must escort space shuttle manned professor gorwin asteroid kryptonite field s.t.a.r lab satellite next section another side-scrolling level set inside satellite superman must battle faulty robot defence system mistaken superman enemy intruder fifth part set outside satellite another asteroid field approaches gameplay identical level three part six similar parts three five rather asteroids superman must fly enemy satellite disrupting signals s.t.a.r lab satellite way must battle darkseid mini-robots large boss robot part seven set outside enemy satellite identified belonging lex luthor superman uses telescopic sight identify attack weak spots avoiding satellite defences final part set inside lex satellite similar part four superman must battle defence robots side-scrolling level object game destroy 'geo-disruptor found end level tynesoft ported published first star boulder dash spy vs. spy acorn platforms uk looking licenses first star held home computer rights superman used tynesoft developed entirely new game many different computers possible versions released home computer platforms day including atari st amiga pc commodore 64 zx spectrum amstrad cpc msx bbc micro acorn electron version apple ii also created us market evidence ever published released game published first star us distributed capstone software 16-bit versions generally received moderately favourable reviews one praised game incorporation style comic book source found gameplay frustrating particularly play sub games sequence gave score 69 amiga version 66 atari st version amiga computing similarly praised look game also pointing top notch sound awarding overall score 62 reception 8-bit versions game much mixed still praising presentation graphics zzap 64 gave c64 version overall score 39 complaining lightweight nature sub games tedious multi-load particular problem loading tape lengthy load level start new game tape would need rewound correct position first level crash gave spectrum version 35 praise given sound even graphics version came criticism including matchstick figure representing superman sideways scrolling section electron user much positive acorn electron version giving overall score 8/10 still criticised multi-load frustrating gameplay
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Computer architecture
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gunship video game gunship combat flight simulator video game developed published microprose 1986 game controlling simulated ah-64 apache helicopter players navigate missions attack enemy targets protect friendly forces commercially critically successful gunship followed gunship 2000 gunship game features missions seven regions including u.s. training southeast asia 1st air cavalry division central america 82nd airborne division middle east 101st airborne division western europe 3rd armored division selection region style enemies pilot assigned primary mission secondary mission could include objectives destroy enemy headquarters support friendly troops i.e destroy targets near friendly forces latter would easier mission battle would fought closer friendly lines pilot arms apache helicopter gunship usually selecting agm-114 hellfire air-to-ground missiles guided missiles destroy hard targets bunkers tanks ffars folding fin aerial rockets unguided rockets destroy soft targets infantry installations hedp high-explosive dual-purpose rounds 30 mm cannon all-purpose weapon maximum range 1.5 km central america middle east western europe aim-9 sidewinders would also standard equipment usually backup air-to-air weapon case cannon failure patient players might move short jumps crouching behind hills block enemy line sight suddenly popping attack aggressive players generally fly fast erratically evade enemy fire flying low deliver devastating cannon attacks close range since flight time component mission evaluation either method advantages latter however rather dangerous 1st line enemies whose fast reaction times cause chopper pummelled relentless fire enemy fire especially small caliber deflected armor cause systems damage enough damaging hits structural integrity fail causing general power failure manifests dual-engine flameout warranting emergency landing emergency landing seriously injured pilot enemy territory causes become missing action pilot lands without serious injury escape back base live fight another day defined time limit game player return number forward area resupply points rearmed refueled damage repaired returning home base end mission ideally pilot completes missions knocks targets makes back base within 20 minutes ending gunship promotions stop pilot makes colonel although continue amassing medals purple heart air medal bronze star silver star distinguished service cross medal honor retire final promotion brig general medals game prerequisites earning others requirement shooting two hinds one mission medal honor led believe possible earn earning lower medals repeated medals harder earn first one criteria winning medals based types targets destroyed number targets destroyed objectives met time elapsed sometimes whether pilot wounded real life medals game awarded posthumously microprose intended gunship simulate urban helicopter akin blue thunder found city graphics difficult instead used tools developed f-15 strike eagle create another military simulation game released 1986 pc dos atari st amiga commodore 64 fm towns msx pc-98 sharp x68000 zx spectrum gunship also ported sega mega drive u.s. gold 1993 however version game differed others featuring arcade-style gameplay horizontal shoot 'em stages gunship microprose third best-selling commodore game late 1987 sales surpassed 250,000 copies november 1989 info magazine gave gunship commodore 64 five stars five describing without qualification best combat flight simulator ever released 8-bit computer praising graphics weapons sound controls physics documentation magazine concluded prime computer gaming world stated reviewer heartily recommends gunship ... five-star rating highest well-deserved 1994 survey wargames magazine gave title three stars five stating initially released helicopter simulation gunship received origins award best screen graphics home computer game 1986 award best simulation game year according readers crash 1987 computer gaming world named gunship action game year 1988 game joined magazine hall fame games highly rated time readers 1996 magazine ranked 102nd best game time follow-up game gunship 2000 released microprose several platforms 1991 1996 successor gunship followed 1999 pc windows
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Computer architecture
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tim bray timothy william bray born june 21 1955 canadian software developer entrepreneur one co-authors original xml specification worked amazon web services since december 2014 previously google sun microsystems digital equipment corporation dec several start-ups bray born june 21 1955 alberta canada grew beirut lebanon returned canada attend school university guelph guelph ontario graduated 1981 bachelor science double majoring mathematics computer science 2009 would return guelph receive honorary doctor science degree tim described switch focus math computer science way math ’ worked like dog cs cs worked much less as—and learned got paid well fresh university bray joined digital equipment corporation dec toronto software specialist 1983 bray left dec microtel pacific research joined new oxford english dictionary oed project university waterloo 1987 manager time bray worked sgml technology would later become central open text corporation xml atom standardization work bray co-founded antarctica systems bray director web technologies sun microsystems early 2004 early 2010 joined google developer advocate 2010 focusing android identity left google march 2014 unwilling relocate silicon valley vancouver started working amazon web services december 2014 bray involved several entrepreneurial activities including tim bray served part-time ceo waterloo maple 1989–1990 waterloo maple developer popular maple mathematical software bray left new oed project 1989 co-found open text corporation two colleagues open text commercialised search engine employed new oed project bray recalled “ 1994 heard conference speaker say search engines would big internet five seconds pieces fell place head realized could build thing technology. ” thus 1995 open text released open text index one first popular commercial web search engines open text corporation publicly traded nasdaq symbol otex 1991 1996 bray held position senior vice president—technology bray along wife dr. lauren wood ran textuality successful consulting practice field web publishing technology contracted netscape 1999 along ramanathan v. guha part create new version meta content framework called resource description framework rdf used xml language 1999 founded antarctica systems vancouver british columbia canada-based company specializes visualization-based business analytics bray contributed several important standards technology particularly web standards world wide web consortium w3c invited expert world wide web consortium 1996 1999 bray co-edited xml xml namespace specifications halfway project bray accepted consulting engagement netscape provoking vociferous protests netscape competitor microsoft supported initial moves bring sgml web bray temporarily asked resign editorship led intense dispute working group eventually solved appointment microsoft jean paoli third co-editor 2001 bray wrote article called taxi future xml.com proposed means improve web client user experience web server system performance via transform-aggregate-send xml-interact architecture—this proposed system similar ajax paradigm popularized around 2005 2001 2004 served tim berners-lee appointee w3c technical architecture group october 2007 bray co-chairing paul hoffman atom-focused atompub working group internet engineering task force atom web syndication format developed address perceived deficiencies rss 2.0 format bray worked ietf json working group 2013 2014 serving editor rfc 7159 specification json data interchange format revised rfc 4627 highlighted interoperability best practices released march 2014 bray written many software applications including bonnie inspiration bonnie++ unix file system benchmarking tool lark first xml processor ape atom protocol exerciser
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Operating systems
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logfs logfs linux log-structured scalable flash file system intended use large devices flash memory written jörn engel part sponsored ce linux forum logfs introduced mainline linux kernel version 2.6.34 released may 16 2010 removed codebase merge window version 4.10 december 2016 unmaintained years seemingly unused logfs mature enough pass entire test suite subsequently included mainline linux kernel marked 'experimental version 2.6.34 released may 16 2010 however attract large user base removed kernel december 2016 logfs motivated difficulties jffs2 larger flash-memory drives logfs stores inode tree drive jffs2 requires scan entire drive mount cache entire tree ram larger drives scan take dozens seconds tree take significant amount main memory logfs avoids penalties work system running uses drive space holding inode tree logfs stores file inode tree drive means write file ancestor node tree must rewritten done wandering tree update lowest node tree i.e. data written first node written ascending tree root inode updated writing root last maintains atomicity update flash-memory block unit erasures usually larger file-system block logfs handles disparity packing multiple file-system blocks single flash-memory block sum entry end flash-memory block records data stored flash-memory block file-system blocks moved deleted erased used new data peak usage flash-memory drive necessary compact data flash-memory blocks full useful data accomplished garbage collection logfs garbage collection strategy relies file data placed certain way flash-memory blocks flash-memory block hold file data level inode tree logfs garbage collect top level trees using 1 empty flash-memory block garbage collect top 2 levels trees using 2 empty flash-memory blocks garbage collect n levels trees using n empty flash memory blocks algorithm exponential time worst case worst case rare algorithm requires reserving handful flash-memory blocks latest logfs source available logfs git tree
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Computer file systems
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zoids battle begins zoids battle begins 1986 battle simulation developed released europe zx spectrum amstrad cpc msx c64 personal computers martech licensed zoids toy manufacturer tomy players control human fused machine known spiderzoid human tasked reclaiming six parts large machine named zoidzilla parts captured enemy red zoids part reclaimed boost power player spiderzoid game well received magazines
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Computer architecture
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norton zone norton zone cloud file sharing online backup tool service operated symantec used share sync access store backup data also allows file collaboration commenting norton zone accessible apps windows windows rt android mac ios platforms norton zone uses encrypted replicated cloud storage provides client-side encryption leading antivirus provider via norton antivirus software symantec distinguishes norton zone competition automatically scanning files malware viruses norton zone offered 5 gb storage free larger storage allocations via subscription june 3 2014 symantec announced norton zone would discontinued august 6 2014
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Distributed computing architecture
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sealing wax sealing wax wax material seal melting hardens quickly paper parchment ribbons wire material forming bond difficult separate without noticeable tampering wax used verify something document unopened verify sender identity example signet ring decoration sealing wax used take impressions seals wax used seal letters close later 16th century envelopes sealing wax romans used bitumen purpose formulas vary major shift european trade indies opened middle ages sealing wax typically made beeswax venice turpentine greenish-yellow resinous extract european larch tree earliest wax uncoloured later wax coloured red vermilion 16th century compounded various proportions shellac turpentine resin chalk plaster colouring matter often vermilion red lead necessarily beeswax proportion chalk varied coarser grades used seal wine bottles fruit preserves finer grades documents situations large seals public documents beeswax used occasion sealing wax historically perfumed ambergris musk scents 1866 many colours available gold using mica blue using smalt verditer black using lamp black white using lead white yellow using mercuric mineral turpeth also known schuetteite green using verdigris users british crown assigned different colours different types documents today range synthetic colours available sealing wax available form sticks sometimes wick granules stick melted one end ignited blackened granules heated spoon normally using flame placed required usually flap envelope wax still soft seal preferably temperature wax best impression quickly firmly pressed released modern day brought sealing wax new level use application traditional sealing wax candles produced canada spain france italy scotland formulations similar used historically since advent postal system use sealing wax become ceremony security modern times required new styles wax allowing mailing seal without damage removal new waxes flexible mailing referred glue-gun sealing wax faux sealing wax flexible sealing wax
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Computer security
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new executable new executable abbreviated ne newexe 16-bit .exe file format successor dos mz executable format used windows 1.0–3.x multitasking ms-dos 4.0 os/2 1.x os/2 subset windows nt version 5.0 windows 2000 ne also called segmented executable first product released using new executable format windows 1.0 1985 followed 1986 multitasking ms-dos 4.0 separate branch ms-dos development released mainstream ms-dos versions 3.2 3.3 sometimes referred european ms-dos 4.0 os/2 1.0 released 1987 target operating system field file header reserves value 01 os/2 02 windows suggesting format designed os/2 already mind joint development agreement ibm microsoft os/2 signed august 1985 months windows 1.0 released november 1985 portable executable pe format replaced ne format 32-bit 64-bit versions windows linear executables lx replaced ne 32-bit programs os/2 designed 16-bit oses ne executables run 32-bit windows beginning windows vista icon resources inside new executables extracted shown even 32-bit shell 64-bit versions windows completely lack native support running ne executables 64-bit windows run 16-bit programs processor without help emulator due rare fairly complex nature files .exe packers support winlite packwin pklite 2.01 slr optloader nelite os/2 ne format also still used non-executable container codice_1 microsoft windows bitmapped fonts new ne linear lx portable pe executables retain dos mz format file header backward compatibility dos run dos so-called dos stub executed usually prints message exits constitutes minimal form called fat binary windows 1.0 executables however file header formatted way dos refuses run program large fit memory error message see windows 1.0 features
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Operating systems
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schema-agnostic databases schema-agnostic databases vocabulary-independent databases aim supporting users abstracted representation data supporting automatic semantic matching queries databases schema-agnosticism property database mapping query issued user terminology structure automatically mapping dataset vocabulary increase size semantic heterogeneity database schemas bring new requirements users querying searching structured data scale become unfeasible data consumers familiar representation data order query center discussion semantic gap users databases becomes central scale complexity data grows evolution data environments towards consumption data multiple data sources growth schema size complexity dynamicity decentralisation scodd schemas increases complexity contemporary data management scodd trend emerges central data management concern big data scenarios users applications demand complete data produced independent data sources different semantic assumptions contexts use typical scenario semantic web data applications evolution databases direction heterogeneous data environments strongly impacts usability semiotics semantic assumptions behind existing data accessibility methods structured queries keyword-based search visual query systems schema-less databases containing potentially millions dynamically changing attributes becomes unfeasible users become aware 'schema vocabulary order query database scale effort understanding schema order build structured query become prohibitive schema-agnostic queries defined query approaches structured databases allow users satisfying complex information needs without understanding representation schema database similarly tran et al defines search approaches require users know schema underlying data approaches keyword-based search databases allow users query databases without employing structured queries however discussed tran et al points users however navigation exploration address complex information needs unlike keyword search used web focuses simple needs keyword search elaborated used obtain complex results instead single set resources goal compute complex sets resources relations development approaches support natural language interfaces nli databases aimed towards goal schema-agnostic queries complementarily approaches based keyword search targeted keyword-based queries express complex information needs approaches explored construction structured queries databases schema constraints relaxed approaches natural language keyword-based search structured queries targeted different degrees sophistication addressing problem supporting flexible semantic matching queries data vary completely absence semantic concern principled semantic models demand schema-agnosticism implicit requirement across semantic search natural language query systems structured data sufficiently individuated concept necessary requirement contemporary database management systems recent works started define model semantic aspects involved schema-agnostic queries consist schema-agnostic queries following syntax structured standard example sql sparql syntax semantics operators maintained different terminologies used maps following sparql query dataset vocabulary maps following sparql query dataset vocabulary consist schema-agnostic queries using keyword queries case syntax semantics operators different structured query syntax 2016 concept schema-agnostic queries developed primarily academia schema-agnostic query systems investigated context natural language interfaces databases semantic web works explore application semantic parsing techniques large heterogeneous schema-less databases recently individuation concept schema-agnostic query systems databases appeared explicitly within literature freitas et al provide probabilistic model semantic complexity mapping schema-agnostic queries
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Databases
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florabase florabase public access web-based database flora western australia provides authoritative scientific information 12,978 taxa including descriptions maps images conservation status nomenclatural details 1,272 alien taxa naturalised weeds also recorded system takes data datasets including census western australian plants western australian herbarium specimen database nearly 725,000 vouchered plant collections operated western australian herbarium within department parks wildlife established november 1998 distribution guide uses combination ibra version 5.1 john stanley beard botanical provinces
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Databases
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merritt method overwrite session consists lead-in random write patterns followed patterns 2-3 executed random order lead-out one random patterns followed 00000000 another random drive written passes even though table shows bit patterns passes specifically targeted encoding scheme end result obscure data drive advanced physical scanning e.g using magnetic force microscope drive likely able recover data series patterns follows
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Computer security
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hang-on game also built versions master system title derived biker turning hang bike bike leaning suzuki read japanese bike magazine though suzuki learned later technique called hang north america nevertheless chose keep former name 1995 interview suzuki said felt hang-on impressive game time release master system version also came two different compilation cartridges one astro warrior one safari hunt using behind motorcycle perspective player races linear race track divided several stages within limited time reaching checkpoint end stage extends time limit game ends time runs race finished arcade game contains in-game billboards bridgestone desert dueler tires shell garelli motorcycles tag john player special cigarettes forum cigarettes marbor obvious parody marlboro cigarettes arcade flyer features bike marlboro colors sponsored yamaha yzr500 world championships mid late 1980s would controversy cigarette ads games marketed children upon release another sega racing game super monaco gp 1989 three arcade cabinet designs—the usual upright machine handlebar brake levers instead joystick buttons upright machine addition seat third version looked roughly like real motorcycle steer player leaned tilt bike steered in-game bike screen mounted windshield area bike sg-1000-exclusive sequel hang-on ii released 1985 though essentially port original game modified work within limitations console hardware 1987 followed sequel super hang-on arcade later range platforms including sega genesis zx spectrum commodore 64 amstrad cpc commodore amiga atari st. polygon based sequel developed genki released sega saturn named variously hang-on gp '95 japan hang-on gp usa hang-on gp '96 europe power drift motorcycle hidden vehicle accessed finishing first place five tracks courses c e. playable extra stage sonic riders hang-on gear super hang-on gear bought shop one playing respective music racing. gear unlockable form sit-down arcade cabinet however collecting 100 rings pressing button race changes gear main music sequel sit-down arcade cabinet outride crisis said game sonic free riders hang-on gear super hang-on gear bought shop original sonic riders shenmue shenmue ii feature hang-on mini-game well ability win miniature toy versions bikes gashapon machines xbox version shenmue ii playable xbox 360 crashes trying play hang-on sonic all-stars racing transformed ryo drives hang-on sit-down arcade cabinet water-based portions race daytona usa h.o entered high score table clip main theme hang-on play
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Computer architecture
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socket g1 socket g1 also known rpga 988a socket g/rpga 989 sockets take socket g1/rpga 988a socket g2/rpga 988b packaged processors intel cpu socket line mobile core i7 successor core 2 line based intel nehalem architecture first available 1366-pin socket b like predecessor lga775 uses lga socket configuration later followed updated lga-1156 socket moved qpi pci-express controller northbridge onto cpu result lower pin count lga-1156 systems later socket g1 systems run dual-channel memory mode opposed triple-channel mode unique lga-1366 platform subsequent xeon sockets nehalem mobile variant released september 23 2009 form i7-720qm 820qm 920xm models followed i7-740qm 840qm 940xm models june 21 2010 newer cpus use new clarksfield core maintained 45 nm manufacturing process desktop-based nehalems nehalem received die shrink january 7 2010 core name westmere intel gma hd graphics ironlake core packaged onto cpu substrate integrated directly processor die goes create arrandale-based line current cpus use package core i7-6x0m series core i5-4x0m series core i5-5x0m series core i3-3x0m series finally pentium p6x00 series celeron p4x00 series released march 28 2010 however available socket g1 available bga package also known pga988 socket processors
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Computer architecture
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movieland movieland also known movieland.com moviepass.tv popcorn.net subscription-based movie download service subject thousands complaints federal trade commission washington state attorney general office better business bureau agencies consumers said held hostage repeated pop-up windows demands payment triggered free 3-day trial period many said never even heard movieland saw first pop-up movieland advertised service spyware personal information would need filled begin free trial federal trade commission ftc filed complaint movieland eleven defendants august 2006 charging engaged nationwide scheme use deception coercion extract payments consumers attorney general state washington also filed complaint charging movieland several defendants violating state computer spyware act consumer protection act movieland advertises movie download service using pop-up ads sites ads offer three-day free trial access members-only content including music news updated sports scores adult movies ads say forms fill need provide credit card number e-mail address making trial appear anonymous site homepage states spyware virus free extra charge site installs program mediapipe used access service movieland.com began operations sometime fall 2005 earlier consumer complaints began soon thereafter consumers claimed never signed free trial never used service never even heard movieland got first pop-up demand payment said found software computers downloading screensaver free utility company denied installed software stealthy means media coverage early january 2006 recounted consumer complaints mentioned several anti-spyware companies buying google advertisements boasting product ability remove movieland report updated february 20 2008 berkman center internet society harvard law school calls movieland mediapipe component badware fully disclose installing completely remove components 'obligations uninstall process modifies software without disclosure richard stiennon it-harvest referred movieland form ransomware due behaviour july 2008 mediapipe report still cited berkman center internet society harvard law school august 8 2006 ftc filed complaint united states district court obtain preliminary permanent injunctive relief rescission contracts restitution disgorgement equitable relief defendants deceptive unfair acts practices violation section 5 ftc act complaint alleged defendants demanding payment fix problem created installing disruptive software could removed reasonable means according ftc complaint movieland repeatedly bombarded consumers pop-up windows accompanied music lasted nearly minute demanded minimum payment 29.95 end recurring pop-up cycle claiming consumers signed three-day free trial cancel service trial period complaint charged pop-ups large dark background took much screen blocking access windows contain close minimize buttons forcing user continue first pop-up showed date time content access software installed system 3 day free trial began text click 'continue purchase license stop reminders graphic reading stop reminders click continue option offered button labeled continue clicking continue brought next pop-up 40-second audiovisual clip featuring woman introduced personal customer service representative stated cancel trial period legally obligated make payment per terms conditions agreed installed content delivery software clip neared conclusion new dialog box entitled payment options appeared choosing close window option ended pop-ups unvarying cycle began addition complaint alleged defendants made numerous false statements attempting collect payments consumers claiming computer owner someone else consented receiving pop-up payment demands paid owner computer received pop-ups legally obligated pay movieland computer owner obligated satisfy contract person entered using computer customer service telephone number provided 900 number consumers called recorded greeting told would incur 34.95 charge hang within three seconds complaint also alleged defendants made difficult impossible consumers uninstall software attempting remove windows control panel add remove programs function redirected web page telling pay 29.95 fee stop pop-ups way many consumers could regain control computers pay fee pay computer technician remove software movieland representatives said downloads spyware get computers accidentally insisting drive-by downloads said ftc lawsuit improperly brought pointed time complaint filed federal judge rejected ftc request temporary restraining order would immediately ended cited billing practices terms service movieland web site warned users cancel pay three-day period pop-up billing reminders would begin appear frequently choose one payment options pay license movieland said pop-ups anti-fraud mechanism received without consumers intentionally downloading software several intentional steps default setting cancel company also stated extrinsic programs adware otherwise bundled software company disputed ftc claim software difficult get rid said could removed using windows control panel following ten companies two individuals named defendants ftc complaint november 2006 defendants ftc signed stipulations governing pre-trial conduct without admitting wrongdoing violation law involvement acts practices alleged complaint defendants agreed make clear prominent disclosures prior software download installation download install software without user explicit consent without disclosing clearly prominently site terms service nature frequency duration pop-up windows may appear regarding purported obligation payment pop-ups also must lock access rest computer also agreed fixed limits many pop-ups generate computer maximum 5 per day 1 per hour requirement provide mute button sound content pop-ups able close windows provide hyperlink toll-free number email utility request stopping pop-ups certain conditions defendants also promised clearly label single-click download install buttons pre-select default also required represent consumers legal contractual obligation pay software unless computer owner provided personal identification agreed pay failure pay result collection proceedings affect computer owner credit status unless owner provided personal identification credit card agreed pay customer service agents may state believe computer owner responsible paying download offer several purchase options including one-time 30-day non-renewing license 29.95 access service terminate ftc complaint scheduled tried united states district court january 2008 trial defendants chose settle court ftc movieland settled ftc september 2007 without admitting wrongdoing violation law defendants agreed make permanent terms pre-trial stipulations including limiting number frequency duration billing pop-ups pay ftc 501,367 reimburse consumers paid program result repeated pop-up demands defendants also agreed stop offering anonymous free trials users certify install time least 18 years age provide install-time link terms service end user license agreement download software reinstalls user removed prominently post removal instructions web sites agreement also requires herd garroni notify ftc change name address employment status new business affiliations five years august 14 2006 rob mckenna attorney general state washington charged movieland digital enterprises herd garroni violating state computer spyware act consumer protection act complaint filed king county superior court seattle alleged misrepresentations unlawful business acts practices similar alleged ftc complaint alleged violations washington state law defendants subject fines 100,000 per violation spyware act 2,000 per violation consumer protection act found liable also subject paying restitution affected consumers alleged violations washington state law included taking control user computer violation spyware act consumer protection act cpa remotely installing billing software initiates controls pop-up cycle misrepresenting ability uninstall software violation acts listing software add/remove programs although software uninstalled unconscionable business practices violation cpa aggressive harassing billing method used failure disclose including use billing method forces payment completely obstructing users access computers threats harassment intimidation billing practices violation cpa threatening collection proceedings adverse effect users credit records fact defendants even know consumer name referring consumers legal obligation pay fact legally binding contract failure disclose material facts violation cpa aggressive relentless threatening form payment demands fact uninstallation option software disabled defendants transmit software user computer surreptitiously misrepresentations violation cpa including stating software contains spyware fact software constitutes spyware behavior announcing suit following seven-month investigation washington attorney general rob mckenna rejected one possible defense defendants claim users legally obligated pay service lacks merit consumers provide knowing consent installation relentless pop-up demands said furthermore computer owners responsible satisfy contracts people including minors entered using computer also said defendants threats collection proceedings adverse effects users credit ratings empty defendants way personally identify computer users assistant attorney general paula selis said tactics forced consumers give pay 20 100 service said sued getting complaints consumers felt harassed held barrel payments n't agree make selis said harassment intimidation consumer using high-pressure tactic make pay something legally obligated pay movieland settled washington april 2007 terms similar ftc settlement specific washington consumers agreeing pay washington 50,000 consumer reimbursement prominently state important contract terms including cost subscription service advertisements
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Computer security
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ann z. caracristi ann zeilinger caracristi february 1 1921 – january 10 2016 american cryptanalyst former deputy director national security agency served various positions 40-year career served member secretary defense joint security commission president foreign intelligence advisory board became first woman nsa promoted gs-18 rank 1975 became chief research operations born bronxville new york attended russell sage college women ’ college troy new york graduated 1942 english history major graduation recruited army signal intelligence service work code breaker recommendation dean russell sage caracristi sent washington d.c. attended cryptanalysis courses william friedman puzzles used train cryptographers art pattern recognition world war ii caracristi cryptography work focused deciphering additive systems used japanese military forces merchant fleet known exceptional talent reconstructing enemy code books colleagues among first americans learn japan planned surrender deciphered code august 14 1945 following war caracristi hired agency would later become part national security agency promoted first supergrade higher civil service paygrade 1959 gs-18 highest supergrade chief research operations 1975 1980 caracristi became sixth nsa deputy director first woman serve role received department defense distinguished civilian service award 1980 highest award given civilians deputy director credited providing leadership new generations code breakers integrating use computers technology retired 1982 continued serve panels intelligence community including president clinton ’ foreign intelligence advisory board appointed 1993 2003 caracristi given honorary degree national intelligence university academic award name given high-performing graduate student year lived adult life one-bedroom cottage georgetown hobbies included birds collecting pewter 2002 name given naval intelligence professionals award caracristi died january 10 2016 washington age 94 dementia later years 1980 received department defense distinguished civilian service award one subjects 2017 non-fiction book code girls untold story american women code breakers world war ii liza mundy
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Computer security
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compiler correctness computing compiler correctness branch computer science deals trying show compiler behaves according language specification techniques include developing compiler using formal methods using rigorous testing often called compiler validation existing compiler compiler validation formal methods involves long chain formal deductive logic however since tool find proof theorem prover implemented software complex high probability contain errors one approach use tool verifies proof proof checker much simpler proof-finder less likely contain errors complete example approach compcert formally verified optimizing compiler large subset c99 methods include model checking formal verification provably correct semantics-directed compiler generation testing represents significant portion effort shipping compiler receives comparatively little coverage standard literature 1986 edition single-page section compiler testing named examples 2006 edition omits section testing emphasize importance “ optimizing compilers difficult get right dare say optimizing compiler completely error-free thus important objective writing compiler correct. ” fraser hanson 1995 brief section regression testing source code available bailey davidson 2003 cover testing procedure calls number articles confirm many released compilers significant code-correctness bugs sheridan 2007 probably recent journal article general compiler testing commercial compiler compliance validation suites available solid sands perennial plum-hall purposes largest body information available compiler testing fortran cobol validation suites common techniques testing compilers fuzzing generates random programs try find bugs compiler test case reduction tries minimize found test case make easier understand
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Programming language topics
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install unix install command unix program used copy files set file permissions implementations offer invoke strip installing executable files
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Computer file systems
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anti-phishing software anti-phishing software consists computer programs attempt identify phishing content contained websites e-mail forms used accessing data usually internet block content usually warning user often option view content regardless often integrated web browsers email clients toolbar displays real domain name website viewer visiting attempt prevent fraudulent websites masquerading legitimate websites popular web browsers comes built-in anti-phishing anti-malware protection services almost none alternate web browsers protections password managers also used help defend phishing mutual authentication techniques study conducted 3sharp company helps businesses manage demo content released september 27 2006 tested ability eight anti-phishing solutions block known phishing sites warn phishing sites allow legitimate sites study commissioned microsoft titled gone phishing evaluating anti-phishing tools windows concluded internet explorer netcraft toolbar effective anti-phishing tools later independent study conducted carnegie mellon university cylab titled phinding phish evaluation anti-phishing toolbars released november 13 2006 tested ability ten anti-phishing solutions block warn known phishing sites block warn legitimate sites exhibit false-positives well usability solution solutions tested netcraft toolbar earthlink scamblocker spoofguard able correctly identify 75 sites tested netcraft toolbar receiving highest score without incorrectly identifying legitimate sites phishing severe problems however discovered using spoofguard incorrectly identified 38 tested legitimate sites phishing leading conclusion inaccuracies might nullify benefits spoofguard offers identifying phishing sites google safe browsing since built firefox internet explorer performed well testing ability detect fresh phishes netcraft toolbar scored high 96 google safe browsing scored low 0 possibly due technical problems google safe browsing testing performed using phishing data obtained anti-phishing working group phishtank unnamed email filtering vendor latest study conducted smartware mozilla released november 14 2006 concluded anti-phishing filter firefox effective internet explorer 10 results study questioned critics noting testing data sourced exclusively phishtank anti-phishing provider study compared internet explorer firefox leaving among others netcraft toolbar opera browser use data phishtank anti-phishing solutions led speculations limited testing data opera netcraft toolbar would gotten perfect score part study two directly aforementioned reports released one day apart asa dotzler director community development mozilla responded criticism mozilla-commissioned report saying 're agreeing recent legitimate data puts firefox ahead good enough since studies conducted microsoft opera software started licensing netcraft anti-phishing data bringing effectiveness browser built-in anti-phishing par netcraft toolbar beyond
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Computer security
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common open policy service common open policy service cops protocol part internet protocol suite defined ietf rfc 2748 cops specifies simple client/server model supporting policy control quality service qos signaling protocols e.g rsvp policies stored servers acted upon policy decision points pdp enforced clients also known policy enforcement points pep two models cops outsourcing model provisioning model considered view client pep outsourcing model simplest cops implementation model policies stored pdp whenever pep needs make decision sends relevant information pdp pdp analyzes information makes decision relays pep pep simply enforces decision provisioning model see rfc 3084 cops usage policy provisioning cops-pr pep reports decision-making capabilities pdp pdp downloads relevant policies pep pep make decisions based policies provisioning model uses policy information base repository policies
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Internet protocols
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hybrid disc hybrid disc disc cd-rom blu-ray disc contains multiple types data used differently different devices include cd-rom music albums containing video files viewable personal computer feature film blu-ray discs containing interactive content used playstation 3 game console hybrid disc optical disc multiple file systems installed typically iso 9660 hfs+ hfs older discs one reason hybrid format restrictions iso 9660 filenames eight characters maximum depths eight directories similar microsoft fat file system another key factor iso 9660 support resource forks critical classic mac os software design os x macos removed much need resource forks application design companies released products dos later windows classic mac os later macos could release cd containing software natively readable either system data files even shared partitions keeping platform specific data separate true shared hybrid hfs filesystem files common iso 9660 hfs partitions stored iso 9660 partition pointing file content hfs area vice versa blizzard entertainment released computer games hybrid cds default mac os 9 macos burn hybrid discs iso 9660/hfs hybrid disc iso 9660 primary volume descriptor makes valid iso 9660 disc apple partition may also apple partition map although necessary iso 9660 portion disc co-exist apple partition header areas define contents disc located different places iso 9660 primary volume descriptor begins 32,768 bytes 32 kb disc present apple partition map begins 512 bytes disc partition map header apple hfs partition known master directory block mdb begins 1,024 bytes disc hybrid-cd also refers audio cd also includes data track storing mp3 digital audio compression format copy cd-da tracks introduction subsequent popularization itunes ipod discs popular sharing music compact disc without requiring recipient extract encode cd-da — technical perhaps time-consuming process older computing hardware however advent faster computing hardware vastly simplified automated extraction encoding tools e.g itunes rhythmbox etc lack automated hybrid feature software popularity hybrid cd subsequently declined however hybrid discs remain commercial setting digital rights management enforcement technique encrypted compressed copies digital audio provided proprietary software listening computer disc drive cd-da included playback stand-alone cd players recent years blu-ray discs released hybrid discs demonstrating compatibility playstation 3 console uses bd primary disc format discs generally include movie feature played blu-ray disc player playable content accessible run playstation 3 console examples include macross frontier itsuwari utahime
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Computer file systems
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proxy server computer networks proxy server server computer system application acts intermediary requests clients seeking resources servers client connects proxy server requesting service file connection web page resource available different server proxy server evaluates request way simplify control complexity proxies invented add structure encapsulation distributed systems proxy server may reside user local computer point user computer destination servers internet open proxy forwarding proxy server accessible internet user 2008 gordon lyon estimates hundreds thousands open proxies internet anonymous open proxy allows users conceal ip address browsing web using internet services varying degrees anonymity however well number methods 'tricking client revealing regardless proxy used reverse proxy surrogate proxy server appears clients ordinary server reverse proxies forward requests one ordinary servers handle request response proxy server returned came directly original server leaving client knowledge original server reverse proxies installed neighborhood one web servers traffic coming internet destination one neighborhood web servers goes proxy server use reverse originates counterpart forward proxy since reverse proxy sits closer web server serves restricted set websites several reasons installing reverse proxy servers content-filtering web proxy server provides administrative control content may relayed one directions proxy commonly used commercial non-commercial organizations especially schools ensure internet usage conforms acceptable use policy content filtering proxy often support user authentication control web access also usually produces logs either give detailed information urls accessed specific users monitor bandwidth usage statistics may also communicate daemon-based and/or icap-based antivirus software provide security virus malware scanning incoming content real time enters network many workplaces schools colleges restrict web sites online services accessible available buildings governments also censor undesirable content done either specialized proxy called content filter commercial free products available using cache-extension protocol icap allows plug-in extensions open caching architecture websites commonly used students circumvent filters access blocked content often include proxy user access websites filter trying block requests may filtered several methods url dns blacklists blacklist url regex filtering mime filtering content keyword filtering products known employ content analysis techniques look traits commonly used certain types content providers blacklists often provided maintained web-filtering companies often grouped categories pornography gambling shopping social networks etc. assuming requested url acceptable content fetched proxy point dynamic filter may applied return path example jpeg files could blocked based fleshtone matches language filters could dynamically detect unwanted language content rejected http fetch error may returned requester web filtering companies use internet-wide crawling robot assesses likelihood content certain type resultant database corrected manual labor based complaints known flaws content-matching algorithms proxies scan outbound content e.g. data loss prevention scan content malicious software web filtering proxies able peer inside secure sockets http transactions assuming chain-of-trust ssl/tls transport layer security tampered ssl/tls chain-of-trust relies trusted root certificate authorities workplace setting client managed organization trust might granted root certificate whose private key known proxy consequently root certificate generated proxy installed browser ca list staff situations proxy analysis contents ssl/tls transaction becomes possible proxy effectively operating man-in-the-middle attack allowed client trust root certificate proxy owns destination server filters content based origin request use proxy circumvent filter example server using ip-based geolocation restrict service certain country accessed using proxy located country access service web proxies common means bypassing government censorship although 3 internet users use circumvention tools cases users circumvent proxies filter using blacklists using services designed proxy information non-blacklisted location proxies installed order eavesdrop upon data-flow client machines web content sent accessed – including passwords submitted cookies used – captured analyzed proxy operator reason passwords online services webmail banking always exchanged cryptographically secured connection ssl chaining proxies reveal data original requester possible obfuscate activities eyes user destination however traces left intermediate hops could used offered trace user activities policies administrators proxies unknown user may fall victim false sense security details sight mind inconvenience risk proxy users may find blocked certain web sites numerous forums web sites block ip addresses proxies known spammed trolled site proxy bouncing used maintain privacy caching proxy server accelerates service requests retrieving content saved previous request made client even clients caching proxies keep local copies frequently requested resources allowing large organizations significantly reduce upstream bandwidth usage costs significantly increasing performance isps large businesses caching proxy caching proxies first kind proxy server web proxies commonly used cache web pages web server poorly implemented caching proxies cause problems inability use user authentication proxy designed mitigate specific link related issues degradation performance enhancing proxy peps typically used improve tcp performance presence high round-trip times high packet loss wireless mobile phone networks highly asymmetric links featuring different upload download rates peps make efficient use network example merging tcp acks acknowledgements compressing data sent application layer translation proxy proxy server used localize website experience different markets traffic global audience routed translation proxy source website visitors browse proxied site requests go back source site pages rendered original language content response replaced translated content passes back proxy translations used translation proxy either machine translation human translation combination machine human translation different translation proxy implementations different capabilities allow customization source site local audience excluding source content substituting source content original local content proxy used automatically repair errors proxied content instance bikiniproxy system instruments javascript code fly order detect automatically repair errors happening browser.. another kind repair done proxy fix accessibility issues anonymous proxy server sometimes called web proxy generally attempts anonymize web surfing different varieties anonymizers destination server server ultimately satisfies web request receives requests anonymizing proxy server thus receive information end user address requests anonymous anonymizing proxy server however degree trust present proxy server user many proxy servers funded continued advertising link user access control proxy servers implement logon requirement large organizations authorized users must log gain access web organization thereby track usage individuals anonymizing proxy servers may forward data packets header lines http_via http_x_forwarded_for http_forwarded may reveal ip address client anonymizing proxy servers known elite high-anonymity proxies make appear proxy server client website could still suspect proxy used client sends packets include cookie previous visit use high-anonymity proxy server clearing cookies possibly cache would solve problem advertisers use proxy servers validating checking quality assurance geotargeted ads geotargeting ad server checks request source ip address uses geo-ip database determine geographic source requests using proxy server physically located inside specific country city gives advertisers ability test geotargeted ads proxy keep internal network structure company secret using network address translation help security internal network makes requests machines users local network anonymous proxies also combined firewalls incorrectly configured proxy provide access network otherwise isolated internet proxies allow web sites make web requests externally hosted resources e.g images music files etc cross-domain restrictions prohibit web site linking directly outside domains proxies also allow browser make web requests externally hosted content behalf website cross-domain restrictions place protect websites likes data theft prohibit browser directly accessing outside domains secondary market brokers use web proxy servers buy large stocks limited products limited sneakers tickets web proxies forward http requests request client regular http request except full url passed instead path request sent proxy server proxy makes request specified returns response web proxies allow http connect method set forwarding arbitrary data connection common policy forward port 443 allow https traffic examples web proxy servers include apache mod_proxy traffic server haproxy iis configured proxy e.g. application request routing nginx privoxy squid varnish reverse proxy wingate ziproxy tinyproxy rabbit4 polipo clients problem complex multiple proxy-servers solved client-serer proxy auto-config protocol pac file socks also forwards arbitrary data connection phase similar http connect web proxies also known intercepting proxy inline proxy forced proxy transparent proxy intercepts normal communication without requiring special client configuration clients need aware existence proxy transparent proxy normally located client internet proxy performing functions gateway router 'transparent proxy proxy modify request response beyond required proxy authentication identification 'non-transparent proxy proxy modifies request response order provide added service user agent group annotation services media type transformation protocol reduction anonymity filtering tcp intercept traffic filtering security feature protects tcp servers tcp syn flood attacks type denial-of-service attack tcp intercept available ip traffic 2009 security flaw way transparent proxies operate published robert auger computer emergency response team issued advisory listing dozens affected transparent intercepting proxy servers intercepting proxies commonly used businesses enforce acceptable use policy ease administrative overheads since client browser configuration required second reason however mitigated features active directory group policy dhcp automatic proxy detection intercepting proxies also commonly used isps countries save upstream bandwidth improve customer response times caching common countries bandwidth limited e.g island nations must paid diversion interception tcp connection creates several issues firstly original destination ip port must somehow communicated proxy always possible e.g. gateway proxy reside different hosts class cross site attacks depend certain behaviour intercepting proxies check access information original intercepted destination problem may resolved using integrated packet-level application level appliance software able communicate information packet handler proxy intercepting also creates problems http authentication especially connection-oriented authentication ntlm client browser believes talking server rather proxy cause problems intercepting proxy requires authentication user connects site also requires authentication finally intercepting connections cause problems http caches requests responses become uncacheable shared cache integrated firewall proxy servers router/firewall host proxy communicating original destination information done method example microsoft tmg wingate interception also performed using cisco wccp web cache control protocol proprietary protocol resides router configured cache allowing cache determine ports traffic sent via transparent redirection router redirection occur one two ways gre tunneling osi layer 3 mac rewrites osi layer 2 traffic reaches proxy machine interception commonly performed nat network address translation setups invisible client browser leave proxy visible web server devices internet side proxy recent linux bsd releases provide tproxy transparent proxy performs ip-level osi layer 3 transparent interception spoofing outbound traffic hiding proxy ip address network devices several methods often used detect presence intercepting proxy server cgi web proxy accepts target urls using web form user browser window processes request returns results user browser consequently used device network allow true proxy settings changed first recorded cgi proxy named rover time renamed 1998 cgiproxy developed american computer scientist james marshall early 1996 article unix review rich morin majority cgi proxies powered one cgiproxy written perl language glype written php language phproxy written php language april 2016 cgiproxy received 2 million downloads glype received almost million downloads whilst phproxy still receives hundreds downloads per week despite waning popularity due vpns privacy methods still several thousand cgi proxies online cgi proxies set purposes making websites accessible disabled people since shut due excessive traffic usually caused third party advertising service means bypass local filtering since many users n't care collateral damage causing became necessary organizations hide proxies disclosing urls take trouble contact organization demonstrate genuine need suffix proxy allows user access web content appending name proxy server url requested content e.g en.wikipedia.org. suffixproxy.com suffix proxy servers easier use regular proxy servers offer high levels anonymity primary use bypassing web filters however rarely used due advanced web filters tor short onion router system intended enable online anonymity tor client software routes internet traffic worldwide volunteer network servers order conceal user location usage someone conducting network surveillance traffic analysis using tor makes difficult trace internet activity including visits web sites online posts instant messages communication forms back user intended protect users personal freedom privacy ability conduct confidential business keeping internet activities monitored onion routing refers layered nature encryption service original data encrypted re-encrypted multiple times sent successive tor relays one decrypts layer encryption passing data next relay ultimately destination reduces possibility original data unscrambled understood transit tor client free software additional charges use network i2p anonymous network 'i2p proxy network aiming online anonymity implements garlic routing enhancement tor onion routing i2p fully distributed works encrypting communications various layers relaying network routers run volunteers various locations keeping source information hidden i2p offers censorship resistance goals i2p protect users personal freedom privacy ability conduct confidential business user i2p runs i2p router computer node i2p router takes care finding peers building anonymizing tunnels i2p provides proxies protocols http irc socks ... software free open-source network free charge use 'proxy refers layer-7 application osi reference model network address translation nat similar proxy operates layer-3 client configuration layer-3 nat configuring gateway sufficient however client configuration layer-7 proxy destination packets client generates must always proxy server layer-7 proxy server reads packet finds true destination nat operates layer-3 less resource-intensive layer-7 proxy also less flexible compare two technologies might encounter terminology known 'transparent firewall transparent firewall means proxy uses layer-7 proxy advantages without knowledge client client presumes gateway nat layer-3 idea inside packet method layer-3 packets sent layer-7 proxy investigation dns proxy server takes dns queries usually local network forwards internet domain name server may also cache dns records client programs socks-ify allows adaptation networked software connect external networks via certain types proxy servers mostly socks
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Computer security
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répertoire international de littérature musicale répertoire international de littérature musicale international repertory music literature internationales repertorium der musikliteratur commonly known acronym rilm nonprofit organization offers digital collections advanced tools locating research topics related music mission “ make knowledge accessible research performance communities worldwide….to include music scholarship countries languages across disciplinary cultural boundaries thereby fostering research arts humanities sciences social sciences. ” central rilm ’ work mission international bibliography scholarship relating facets music research rilm founded 1966 american musicologist barry s. brook 1918–1997 joint sponsorship international musicological society ims international association music libraries archives documentation centres iaml 2007 international council traditional music ictm joined third sponsoring organization 1967 1968 rilm developed first set computer programs automated processing sorting bibliographic records author/subject indexes ran first mainframe ibm computer ibm system/360 computing center city university new york s/360 delivered ibm 1964 time advanced computing machine original ibm s/360 software later migrated ibm system/370 used production rilm abstracts twenty years 1969 1988 rilm ’ development procedures computerized data processing immediately adopted répertoire international de littérature ’ art rila founded upon rilm ’ model started publishing abstracts 1975 1979 rilm entered agreement lockheed research laboratory palo alto division lockheed missiles space company inc. distribution data telephone lines later agreement transferred dialog information retrieval services although available online already advent internet end twentieth century primary medium distribution bibliographic records printed volumes 1993 onward rilm longer available dialog information retrieval service 1989 national information service corporation nisc baltimore released rilm abstracts music literature cd-rom 1990s rilm abstracts became available online nisc muse 1993–2010 oclc first search 1994–2010 ovid/silverplatter 2002–2010 cambridge scientific abstracts/proquest 2002–2010 platforms rilm databases currently exclusively available ebsco information services rilm ’ first editorial office located queens college city university new york 1967–68 graduate center cuny provided institutional context rilm ’ international center since 1968 rilm staff 40 employees editors technology experts administrators governed guided board directors advisory committee commission mixte international consists appointed members international musicological society ims international association music libraries archives documentation centres iaml international council traditional music ictm barry brook ’ second report published march 1968 issue notes details deliberations commission mixte worked establish procedures functioning rilm rilm abstracts music literature rilm abstracts music literature covers significant international scholarship printed digital media language published since august 1967 consists citations articles single-author books collections essays bibliographies catalogues master ’ theses doctoral dissertations festschriften films videos technical drawings instruments facsimile editions iconographies commentaries included critical editions music ethnographic recordings conference proceedings reviews web resources well 3500 periodicals dovetail coverage répertoire international de la presse musicale differs music periodical indexes coverage books abstracts indexing broad international yet selective coverage entry provides title original language english translation title full bibliographic data abstract detailed index help convey “ aboutness ” record amplified online relevance-based order display individual record many non-english entries also include abstract language publication following unesco model rilm abstracts conceived cooperative national committees responsible contributing bibliographic citations abstracts publications issued respective countries international office new york today committees contribute 15,000 records annually edited indexed added online database another 35,000 records per year produced editors international office bibliographic information abstracts—as well journals yet covered rilm—can also submitted directly international center new york rilm abstracts music literature first abstracted bibliography humanities designated american council learned societies acls pilot project development computerized bibliographical system humanities serve model 30 constituent scholarly societies acls time rilm abstracts published print subject thesaurus name equivalencies led users preferred terms translated seventeen languages alphabetically integrated subject index practice allowed users find desired english-language term spelling personal name initiating search language familiar gradually rilm abstracts expanded multilingual environment database includes besides standard english-language abstracts also abstracts language publication languages whenever available mid-2000s rilm abstracts began expand coverage asian publications music scholarship published chinese periodicals concurrently elements bibliographic records publications issued non-roman writing systems offered bilingual rilm abstracts music literature appeared 1967 1983 triannual printed volumes indexes corresponding annual volumes well cumulative indexes corresponding five-year periods 1984 1999 annual volumes corresponding indexes since 2000 available exclusively online ebsco host rilm abstracts music literature full text july 2016 rilm abstracts music literature expanded addition music periodicals full-text rilm abstracts music literature full text raft offers access 240 music periodicals 50 countries coverage also includes reviews well obituaries editorials correspondence advertisements news published early twentieth century present addition metadata abstracts indexing raft offers searching browsing tools full-text issue cover cover database updated monthly details title ’ current coverage found title list rilm.org/fulltext new titles added time rilm music encyclopedias december 2015 rilm launched rilm music encyclopedias rme 41 titles librarian laurie sampsel asserts “ cross searching full text many titles yields results impossible highly unlikely find using print versions encyclopaedias. ” stephen henry mentions rme ’ “ ability provide access excellent european resources might otherwise available libraries less comprehensive collections. ” rme ’ titles stem different periods countries earliest jean jacques rousseau ’ dictionnaire de musique published 1775 also first edition “ grove ” edition published theodore presser 1895 largest amount titles date 2000 onward among ken bloom ’ broadway lol henderson lee stacey ’ encyclopedia music 20 century peter matzke et al. das gothic- und dark wave-lexikon richard kostelanetz ’ dictionary avant-gardes comprehensive conceived 1972 bis 2006 also included rme holds important titles ethnomusicologists among garland encyclopedia world music eileen southern ’ biographical dictionary afro-american african musicians first single comprehensive volume kind collection expands annually additions four titles average one titles regularly updated new articles additions existing articles titles listed rilm music encyclopedias index printed music 1 july 2018 rilm assumed ownership ipm previously owned james adrian music company founded 2000 george r. hill index printed music ipm digital finding aid searching specific musical works contained printed collections sets series indexes individual pieces music printed complete works composers anthologies containing pieces disparate historical periods scholarly editions provides granular level detail piece including performing forces language multiple clefs figured bass ipm includes complete contents collected editions historical series sets monuments music bibliography george r. hill norris l. stephens berkeley fallen leaf press 1997 turn based upon anna h. heyer ’ historical sets collected editions monuments music guide contents american library association 1957–1980 since 2019 ipm offers new features among biographical facts identifying composers editors lyricists hyperlinks open-access editions music incipits works otherwise difficult distinguish easy toggling collections individual works contained therein expanded search filters enable refined searching place date publication document type genre language text bibliolore rilm hosts blog bibliolore whose posts direct relationships content found rilm abstracts music literature enhancement rilm abstracts music literature full text well rilm music encyclopedias mgg online index printed music new posts appear every week many celebrate round birthdays musical figures anniversaries since inception 2009 bibliolore published 1300 posts viewed 500,000 times 1967 1999 rilm published rilm abstracts music literature print first quarterly later annually 1999 volume last print volume largest 19,619 records since 1972 rilm also published print volumes rilm retrospectives series topical bibliographies commenced first edition barry s. brook ’ thematic catalogues music annotated bibliography stuyvesant ny pendragon press 1972 recent volumes published series include speaking music music conferences 1835–1966 2004 annotated bibliography 5948 papers musical topics presented 447 conferences building previous efforts volume stays true brook ’ original vision expanding upon well covers 130 years conference proceedings worldwide scope though western europe remains focus subsequent volume liber amicorum festschriften music scholars nonmusicians 1840–1966 annotated bibliography catalogue 574 festschriften totaling 118 pages 715 entries next part volume totaling 355 pages 3881 entries documents articles pertaining music found listed festschriften preceded introductory history festschriften volumes principally devoted research materials published rilm issued first volume 1967 rilm perspectives series conference proceedings explores topics related organization ’ global mission inaugural volume music ’ intellectual history founders followers fads 2009 based papers presented conference history music historiography held graduate center cuny 16–19 march 2005 rilm issued two editions comprehensive style guide write music rilm manual style second edition introduces material included 2005 publication well revisions based suggestions readers manual differs significantly generalized style guides mla apa explicating matters gender-neutral language dead language punctuation serial comma em dash lens music manual specifically suited students rilm developed stand-alone platform advanced search browse capabilities host distribute music reference works beginning authoritative german-language music encyclopedia die musik geschichte und gegenwart mgg platform facilitates automatic translation content 100 languages via google translate integration user accounts annotations notes created saved shared cross references linking related content throughout mgg online links related content rilm abstracts music literature others well interface compatible mobile tablet devices search function hailed powerful easy-to-use tool different options available limiting search results specific search results easily located preview section mgg online based second edition includes continuous updates revisions additions platform allows user access earlier versions revised articles platform currently developed knowledge exchange
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Databases
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dos plus dos plus erroneously also known dos+ first operating system developed digital research oem support group newbury berkshire uk first released 1985 dos plus 1.0 based cp/m-86 plus combined pcmode emulator concurrent pc dos 4.11 cp/m-86 plus concurrent dos 4.1 still developed us concurrent pc dos 4.11 internationalized bug-fixed version brought forward digital research uk later dos plus 2.x issues based concurrent pc dos 5.0 instead broader picture dos plus seen intermediate step concurrent cp/m-86 dr dos dos plus able run programs written either cp/m-86 ms-dos 2.11 read write floppy formats used systems four cp/m-86 programs multitasked one dos program run time dos plus attempts present command-line interface ms-dos like ms-dos command-line interpreter called codice_1 alternative name codice_2 codice_3 file codice_4 except fiddload extension load field-installable device drivers fidd versions dos plus 2.1 major difference user notice bottom line screen contains status information similar left-hand side status bar shows running processes leftmost one visible screen others running background right-hand side shows keyboard layout use uk8 example printer port assignment keyboard caps lock num lock status current time dos program running status line shown dos programs run background keyboard layout use changed pressing ctrl alt one function keys f1-f5 dos plus contains number extra commands support multitasking features also contains subsets standard dos commands cp/m commands – example built-in codice_5 command codice_6 utility copy files codice_7 command assign one three drives n p directory different drive similar manner ms-dos command codice_8 example cause directory codice_9 appear drive n so-called floating drive feature allows old programs n't support subdirectories work dos plus used make file handling command prompt much easier feature also present concurrent dos multiuser dos system manager 7 real/32 however systems extent concept unused drive letters z except drive letter l dr dos 3.31 6.0 november 1992 updates bdos 6.7 also support including drive letter l later systems 4dos/ndos command processor supports features well floating drives implemented bdos kernel command line shell thus feature also used within dos applications entering directory paths long application parse split dirspec processing using similar feature concurrent dos multiuser dos system manager real/32 dynamically assign floating drive l load path loaded application thereby allowing applications refer files residing load directory standardized drive letter instead fixed absolute path load drive feature makes much easier move software installations across disks without adapt paths overlays configuration files user data stored load directory subsequent directories similar reasons appendage environment block associated loaded applications ms-dos/pc dos 3.0 higher contains reference load path executable however consumes resident memory take advantage support must coded executable whereas dri solutions transparently works kind application another feature resulting bdos internal organization current working directories relative links parent directories theoretically unlimited directory depth supported mentioned operating systems – contrast ms-dos/pc dos dr dos since 1992 ms-dos compatible internal data structure named current directory structure cds limits directory depths maximum 66 characters features attributed fact cp/m concept subdirectories dos emulated operating systems directories translated internal cp/m structures intelligent way dos plus boots single file called either dosplus.sys netplus.sys rather io.sys msdos.sys combination ms-dos file cp/m-86 cmd format structured internally number modules dos plus main operating system rom philips originally developed pc compatible versions supplied amstrad pc1512 t.r.a.n yasmin turbo non-ibm pc compatible bbc master 512 came dos plus 1.2 1.2a 2.1 successor solidisk pc plus also came variant dos plus 1.2a 2.1 dos plus 2.1e/g adaptations apricot act series non-standard 315 kb 720 kb fat12 floppy formats logical sectored fat hard disk format partition type 0xf2 sperry pcs 80186 co-processor boards acorn archimedes a300 a310 well acorn 286 prototypes supported well known operating system versions include
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Operating systems
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gecko software gecko browser engine developed mozilla used firefox browser thunderbird email client many projects gecko designed support open internet standards used different applications display web pages cases application user interface rendering xul gecko offers rich programming api makes suitable wide variety roles internet-enabled applications web browsers content presentation client/server gecko written c++ javascript since 2016 additionally rust free open-source software subject terms mozilla public license version 2 mozilla officially supports use android linux macos windows development layout engine known gecko began netscape 1997 following company purchase digitalstyle existing netscape rendering engine originally written netscape navigator 1.0 upgraded years slow comply well w3c standards limited support dynamic html lacked features incremental reflow layout engine rearranges elements screen new data downloaded added page new layout engine developed parallel old intention integrate netscape communicator mature stable least one major revision netscape expected released old layout engine switch launch mozilla project early 1998 new layout engine code released open-source license originally unveiled raptor name changed nglayout next generation layout due trademark problems netscape later rebranded nglayout gecko mozilla organization forerunner mozilla foundation initially continued use nglayout name gecko netscape trademark eventually gecko branding october 1998 netscape announced next browser would use gecko still called nglayout time rather old layout engine requiring large parts application rewritten decision popular web standards advocates largely unpopular netscape developers unhappy six months given rewrite also meant work done netscape communicator 5.0 including development mariner improvements old layout engine abandoned netscape 6 first netscape release incorporate gecko released november 2000 name netscape 5 never used gecko development continued applications embedders began make use america online time netscape parent company eventually adopted use compuserve 7.0 aol mac os x products previously embedded internet explorer however exception betas gecko never used main microsoft windows aol client july 15 2003 aol laid remaining gecko developers mozilla foundation formed day became main steward gecko development today gecko developed employees mozilla corporation employees companies contribute mozilla project volunteers outset gecko designed support open internet standards standards gecko supports include gecko also partially supports svg 1.1 svg font color profile animation view cursor modules yet implemented filter text modules partially implemented extensibility module also implemented currently disabled order support web pages designed legacy versions netscape internet explorer gecko supports doctype switching documents modern doctype rendered standards compliance mode follows w3c standards strictly documents doctype older doctype rendered quirks mode emulates non-standard oddities netscape communicator 4.x however 4.x features layers supported gecko also limited support non-standard internet explorer features marquee element codice_1 property though pages explicitly testing codice_1 told supported gecko primarily used web browsers earliest netscape 6 mozilla suite later renamed seamonkey also used mozilla web browser derivatives firefox firefox mobile implementation internet explorer-clone part wine mozilla also uses thunderbird email-client web browsers using gecko include gnu icecat waterfox k-meleon lunascape portable firefox conkeror classilla tenfourfox products using gecko include nightingale instantbird google picture-organization software picasa linux gecko also used sugar olpc xo-1 computer gecko used complete implementation xul xml user interface language gecko currently defines xul specification products historically used gecko include pale moon currently using goanna songbird epiphany known gnome web gnome devhelp replaced gecko webkitgtk sunbird calendar web browsers including swiftfox flock galeon camino minimo beonex communicator kazehakase microb windows platforms gecko depends proprietary compilers thus foss distributions linux include gecko package used windows compatibility layer wine gecko 2.0 version number bumped 5.0 match firefox 5 kept sync major version number firefox thunderbird reflect fact longer separate component netscape era combination poor technical management decisions resulted gecko software bloat thus 2001 apple chose fork khtml gecko create webkit engine safari browser however 2008 mozilla addressed bloat problems resulting big performance improvements gecko october 2016 mozilla announced quantum ongoing project encompassing several software development efforts build next-generation web engine firefox users includes numerous improvements gecko taken experimental servo project firefox 57 also known firefox quantum first shipping november 2017 initial version major components quantum/servo projects enabled include increased performance css gpu rendering components additional components merged servo gecko incrementally future versions quantum mozilla project encompassing several software development efforts build next-generation web engine firefox users includes numerous improvements gecko largely incorporated experimental servo project quantum also includes refinements user interface interactions firefox 57 released november 2017 initial version servo component enabled mozilla dubs several planned future releases firefox quantum 2013 mozilla began experimental servo project engine designed scratch goals improving concurrency parallelism also reducing memory safety vulnerabilities important factor writing servo rust programming language also created mozilla designed generate compiled code better memory safety concurrency parallelism compiled c++ code april 2016 servo needed least several years development become full-featured browser engine thus decision start quantum project bring stable portions servo firefox quantum project composed several sub-projects
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Web technology
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simple protocol independent computing environments computing spice simple protocol independent computing environments remote-display system built virtual environments allows users view computing desktop environment – computer-server machine also anywhere internet – using wide variety machine architectures qumranet originally developed spice using closed-source codebase 2007 red hat inc acquired qumranet 2008 december 2009 released code open-source license made protocol open standard spice client connection remote desktop server consists multiple data channels run separate tcp unix socket connection data channel designated operate either clear-text tls modes allowing administrator tradeoff security level vs performance tls mode provides strong encryption traffic transmitted data channel addition encryption spice protocol allows choice authentication schemes original spice protocol defined ticket based authentication scheme using shared secret server would generate rsa public/private keypair send public key client client would encrypt ticket password public key send result back server would decrypt verify ticket current spice protocol also allows use sasl authentication protocol thus enabling support wide range admin configurable authentication mechanisms particular kerberos one server implementation exists several programmers developed new implementations spice client-side since open-sourcing spice spice protocol originated provide improved remote desktop capabilities fork kvm codebase
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Internet protocols
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philips vg-8020 vg 8020 philips third msx 1 computer vg8000 even printer port vg8010 computers version real keyboard chiclet keyboard like predecessors vg-8020 released 1984 featured zilog z80a microprocessor clocked 3.56 mhz 64kb ram 16kb vram two cartridge slots
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Computer architecture
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chess titans chess titans chess game 3d graphics developed oberon games included windows vista windows 7 home premium business/professional enterprise ultimate fully animated photorealistic interactive game ten difficulty levels played two participants one player computer game publicly introduced windows vista build 5219 another chess program known simply chess bundled microsoft entertainment pack 4 developed david norris former microsoft employee author chess engine ziggurat game fully animated designed windows aero glass-like view game features photorealistic board rotated 3d themes available chess pieces board showcases 3d capabilities vista game played either mouse keyboard gamepad controller windows also played windows media center using remote control provided tv tuner cards certain laptops well player turn chess titans displays last move made opponent player also click chess piece highlight valid moves piece features turned options dialog box chess titans ten difficulty levels selected options dialog box player also choose whether play black white playing computer first time player prompted choose initial difficulty level beginner level 2 intermediate level 5 advanced level 8 chess titans keeps record many games player drawn lost computer difficulty level two-player game chess board automatically turns 180 degrees opposite player move option turned chess titans saves two-player game scores
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Operating systems
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phorm phorm formerly known 121media digital technology company known contextual advertising software phorm incorporated delaware united states relocated singapore phorm corporation singapore ltd 2012 founded 2002 company originally distributed programs considered spyware made millions dollars revenue stopped distributing programs complaints groups united states canada announced talking several united kingdom internet service providers isps deliver targeted advertising based websites users visited phorm partnered isps oi telefonica brazil romtelecom romania ttnet turkey june 2012 phorm made unsuccessful attempt raise £20 million 20 stake chinese subsidiary company proposed advertising system called webwise behavioral targeting service similar nebuad used deep packet inspection examine traffic phorm said data collected would anonymous would used identify users service would include protection phishing fraudulent collection users personal information nonetheless world wide web creator tim berners-lee others spoke phorm tracking users browsing habits isp bt group criticised running secret trials service uk information commissioner office voiced legal concerns webwise said would legal opt-in service opt-out system european commission called uk protect web users privacy opened infringement proceeding country regard isps use phorm groups including amazon.com wikimedia foundation non-profit organization operates collaborative wiki projects requested opt-out websites scans system phorm changed opt-in policy according phorm ’ website company would collect data users explicitly opted services users provide separate consent web browsing device used phorm ceased trading 14 april 2016 previous incarnation 121media company made products described spyware register 121media distributed program called peopleonpage classified spyware f-secure peopleonpage application built around advertising engine called contextplus contextplus also distributed rootkit called apropos used tricks prevent user removing application sent information back central servers regarding user browsing habits center democracy technology u.s.-based advocacy group filed complaint u.s. federal trade commission november 2005 distribution considered spyware including contextplus stated investigated uncovered deceptive unfair behaviour complaint filed concert canadian internet policy public internet center group filing similar complaint integrated search technologies canadian authorities contextplus shut operations may 2006 stated longer able ensure highest standards quality customer care shutdown came several major lawsuits adware vendors launched september 2007 121media become known phorm admitted company history adware stated closed multimillion-dollar revenue stream peopleonpage toolbar citing consumers ’ identification adware spyware primary cause decision early 2008 phorm admitted editing article wikipedia—removing quotation guardian commercial executives describing opposition towards tracking system deleting passage explaining bt admitted misleading customers covert phorm trials 2007 changes quickly noticed reversed online encyclopedia editors phorm currently resides mortimer street london uk staffing levels around 35 trading phorm shares suspended london aim market 24 february 2016 pending clarification company financial position according phorm unable secure requisite equity funding ... advanced discussions certain shareholders parties regarding possible alternative financing ... guarantee discussions would result funds raised pending conclusion discussions company requested suspension shares trading aim company made loss 32.1 million 2007 loss 49.8 million 2008 loss 29.7 million 2009 2010 means better net loss 27.9 million end 2010 company lost 107 million perceivable revenue stream 2011 phorm reported losses 30.5 million conducted equity placing £33.6 million paid company debt 14 april 2016 phorm board directors announced london stock exchange company ceasing trade shareholders unlikely recover investments according rns number 2561y ftse 13 may 2016 changes ftse uk index series ftse aim all-share index effective start trading 18 may 2016 phorm worked major u.s. british isps—including bt group formerly british telecom virgin media talktalk time owned carphone warehouse —on behavioral targeting advertisement service monitor browsing habits serve relevant advertisements end user phorm say deals would given access surfing habits 70 british households broadband service uses deep packet inspection check content requested web pages compared nebuad front porch service would marketed end-users webwise 2009 bbc took legal advice trade mark webwise would work categorising user interests matching advertisers wish target type user browse 're able categorise internet actions said phorm coo virasb vahidi actually see entire internet company said data collected would completely anonymous phorm would never aware identity user browsed adds phorm advertising categories exclude sensitive terms widely drawn reveal identity user monitoring users browsing phorm even says able offer protection online fraud phishing phorm formerly maintained opt-out policy services however according spokesman phorm way opt-out works means contents websites visited still mirrored system computers users http applications used user computer need configured supplemented add ons opt since declared information commissioner office phorm would legal uk law opt-in service richard clayton cambridge university security researcher attended on-the-record meeting phorm published account advertising system implemented phorm system like many websites uses http cookies small pieces text store user settings company said initial web request redirected three times using http 307 responses within system inspect cookies determine user opted system sets unique phorm tracking identifier uid user collects already exists adds cookie forged appear come requested website analysis titled stealing phorm cookies clayton wrote phorm system stores tracking cookie website visited user pc contains identical copy user uid possible phorm system strips tracking cookies http requests forwarded across internet website server prevent uid sent websites using https would allow websites associate uid details website collects visitor phorm senior vice president technology marc burgess said collected information also includes timestamp burgess said enough information accurately target ad future used find b browsed 2008 phorm considered offering incentive addition phishing protection originally planned means convince end-users opt webwise system alternate incentives suggested toluna.com market research survey carried behalf phorm included phishing protection donation charity free technical support line one pound opted-in users monthly broadband subscriptions following decision wikimedia foundation amazon opt websites profiled phorm webwise system incentive websites remain opted phorm profiling system phorm launched webwise discover korean launch web publisher incentive announced press conference covent garden london 3 june 2009 survey polling firm populus revealed watching demonstration video 66 2,075 individuals polled claimed either like idea like lot website publishers invited upload web widget provide small frame display recommended web links based tracked interests phorm-tracked website visitors whose isp uses phorm deep packet inspection intercept profile web traffic would charge website phorm stand make money webwise discover however plans display targeted adverts future widget would deliver link recommendations user signed targeted advertising phorm-affiliated isp widget would invisible everyone else.. press launch phorm spokespersons admitted present single uk isp website yet signed webwise discover system although emphasised part current korea telecom webwise trials legal advice offered websites considering signing oix system susan singleton open rights group org raised questions phorm legality asked clarification service would work fipr argued phorm online advert system illegal uk nicholas bohm general counsel fipr said need parties consent interception order lawful extremely basic principle within legislation lightly ignored treated technicality open letter information commissioner published fipr web site conservative peer lord northesk questioned whether uk government taking action targeted advertising service offered phorm light questions legality data protection regulation investigatory powers acts 9 april 2008 information commissioner office ruled phorm would legal uk law opt-in service office stated closely monitor testing implementation phorm order ensure data protection laws observed uk home office indicated phorm proposed service legal users give explicit consent office became subject controversy emails phorm released emails showed company edited draft legal interpretation office official responded agree becomes position think clients prospective partners comforted liberal democrat spokeswoman home affairs baroness sue miller considered act collusion fact home office asks company worried actually falling outside laws whether draft interpretation law correct completely bizarre register reported may 2008 phorm logo strongly resembled unrelated uk company called phorm design quoted smaller company owner simon griffiths 've solicitors look say 'd go court phorm obviously big player lot clout 'm small design agency sheffield employs three people 21 september 2010 phorm webwise service also shared name bbc webwise monitoring phorm website using website change detection service alerted interested parties changes 21 september 2010 phorm website edited remove references word 'webwise phorm webwise product become 'phormdiscover office harmonization internal market ohim trade marks designs registration office european union website ctm-online database lists phorm application use 'webwise trade mark name british broadcasting corporation listed opponent grounds 'likelihood confusion city london-based legal firm bristows wrote ohim 22 september 2010 withdrawing bbc opposition saying british broadcasting corporation instructed us request withdrawal opposition b11538985 28 october 2010 bt removed webwise pages company website although 12 november 2010 pages finally confirmed removed forum contributors campaign group called nodpi.org virgin media removed phorm webwise faqs customer-news section european union communications commissioner viviane reding said commission concerned phorm breaching consumer privacy directives called uk government take action protect consumers privacy european commission wrote uk government 30 june 2008 set context eu interest controversy asked detailed questions ahead possible commission intervention required uk respond letter one month sent spokeswoman department business enterprise regulatory reform berr admitted 16 august uk met deadline 16 september berr refused register request release full text reply european commission released statement effect uk authorities consider phorm products capable operated lawful appropriate transparent fashion unsatisfied response european commission wrote uk 6 october martin selmayr spokesman reding information society media directorate-general said us matter finished quite contrary uk government responded november commission sent another letter government january 2009 third letter sent commission satisfied explanations implementation european law context phorm case selmayr quoted register saying european commission investigation regard phorm case still ongoing went say commission may proceed formal action uk authorities provide satisfactory response commission concerns 14 april european commission said opened infringement proceeding united kingdom regarding isps use phorm day response news item register regarding european commission preparations sue uk government phorm said technology fully compliant uk legislation relevant eu directives confirmed berr uk regulatory authorities note suggestion contrary commission statement today however berr denied confirmation responded freedom information foi request also made day january 2012 eu dropped case uk government initial reaction proposed service highlighted deep concerns regards individual privacy property rights data phorm defended technology face called misinformation bloggers claiming threatens users privacy security firms classify phorm targeting cookies adware kaspersky lab whose anti-virus engine licensed many security vendors said would detect cookie adware trend micro said high chance would add detection tracking cookies adware pc tools echoed trend concerns privacy security urging phorm apply opt-in approach specialist anti-spyware firm sunbelt software also expressed concerns saying phorm tracking cookies candidates detection anti-spyware software ross anderson professor security engineering cambridge university said message care privacy use bt virgin talk-talk internet provider added historically anonymising technology never worked even stressed still posed huge privacy issues phorm engaged number public relations advisers including freuds citigate dewe rogerson ex-house commons media adviser john stonborough attempt save reputation engaged audiences via moderated online webchats creator world wide web sir tim berners-lee criticised idea tracking browsing history saying mine ca n't want use something negotiate agree understand 'm getting return also said would change isp introduced phorm system director world wide web consortium berners-lee also published set personal design notes titled snooping explains views commercial use packet inspection references phorm simon davies privacy advocate founding member privacy international said behavioural advertising rather spooky concept many people separate role 80/20 thinking consultancy start-up engaged phorm look system said impressed effort put minimising collection personal information subsequently quoted saying privacy international endorse phorm though applaud number developments process system appear mitigate number core privacy problems profiling retention tracking ... wo n't pi support system works opt-out basis kent ertugrul later said made mistake suggested privacy international endorsed phorm confusion apologise endorsement fact simon davies md 80 20 also director privacy international ertugrul set website called stopphoulplay.com reaction phorm critics alexander hanff marcus williamson ertugrul called hanff serial agitator run campaigns phorm companies procter gamble says williamson trying disgrace ertugrul phorm serial letter writing hanff believes stopphoulplay website statements completely irrelevant campaign backfire ertugrul williamson laments phorm stooped personal smears launched 28 april 2009 stopphoulplay.com discussed petition uk prime minister downing street website originally launched web page claimed website managers 10 downing street recognised mistake allowing misleading petition appear site since provided assurances phorm permit happen day freedom information foi act used request confirmation claim phorm 29 april phorm removed quoted text website replaced nothing prime minister office replied foi request 28 may stating held information relation request concerning phorm claim day site launch bbc correspondent darren waters wrote battle sign ceasefire sides nowiki phorm anti-phorm campaigners /nowiki settling war attrition governments uk eu drawn crossfire site closed september 2009 redirects main phorm site initial denials bt group confirmed ran small scale trial one exchange prototype advertising platform 2007 trial involved tens thousands end users bt customers able opt trial—bt said developing improved non-cookie based opt-out phorm—but decision made post-trial approach register reported bt ran earlier secret trial 2006 intercepted profiled web browsing 18,000 broadband customers technical report states customers participated trial made aware profiling one aims validation affect experience 4 june 2008 copy 52-page report allegedly inside bt titled pagesense external technical validation uploaded wikileaks report angered many members public questions regarding involvement charity ads oxfam make trade fair sos children villages whether made aware ads used many feel highly illegal technical trials fipr nicholas bohm said trials online ad system carried bt involving 30,000 customers potentially illegal bt third trial phorm webwise system repeatedly slipped trial last approximately two weeks 10,000 subscribers originally due start march 2008 pushed april end may yet occur company facing legal action trials phorm carried without user consent 2 september 2008 investigating complaint made anti-phorm protestors city london police met bt representatives informally question secret phorm trials 25 september police announced formal investigation bt secret trials phorm 2006 2007 according alex hanff police said criminal intent behalf bt implied consent service going benefit customers bohm said police response 29 september 2008 announced bt support forum trial phorm webwise system would commence following day bt press officer adam liversage stated bt still working network-level opt-out offered trial opted-out traffic pass webwise system mirrored profiled final full roll-out webwise across bt national network necessarily depend completion work either open rights group urged bt customers participate bt webwise trials saying anti-fraud feature unlikely advantages features already built web browsers subscribers bt forums used beta forums criticise raise concerns bt implementation phorm bt responded statement according kent ertugrul bt would completed rollout software end 2009 wall street journal however reported july 2009 bt plans concentrating opportunities phorm share price fell 40 news 6 july 2009 bt former chief press officer adam liversage described thoughts using twitter year intensive personal-reputation-destroying pr trench warfare comes nothing ended comment phantastic october 2009 sergeant mike reed city london police answered freedom information foi request confirmed crime reference number 5253/08 response stated originally passing case papers crown prosecution service cps december 2008 police asked provide evidence cps october 2009 asked disclose date investigation reopened said instruction cps october 2009 sergeant reed response named officer charge d/s murray 25 february 2010 reported cps continued work potential criminal case bt secret trials phorm system prosecutors considered whether press criminal charges unnamed individuals part regulation investigatory powers act april 2011 cps decided prosecute would public interest stating neither phorm bt acted bad faith penalty imposed would nominal april 2012 reports said officer city london police taken lunch phorm police spokesperson quoted saying aware allegation formal complaint received force reviewing information available deciding best course action spokesperson also highlighted city london police involved investigation bt phorm decision investigate prompted cps advice advertisers initially expressed interest phorm include financial times guardian universal mccann myspace ivillage mgm omd virgin media unanimis guardian withdrawn targeted advertising deal phorm email reader advertising manager simon kilby stated true conversations phorm regarding services concluded time want part network decision small part conversations internally product sits values company response article published register 26 march 2008 phorm stated myspace joined oix publisher financial times decided participate phorm impending trial org jim killock said many businesses think commercial data relationships simply private customers decide might even believe data spied upon form industrial espionage david evans british computer society questioned whether act publishing website net giving consent advertisers make use site content monitor site interactions customers pete john created add called dephormation servers web users opt remain opted-out system however john ultimately recommends users switch phorm-equipped internet providers dephormation solution fig leaf privacy rely dephormation protect privacy security need find new isp april 2009 amazon.com announced would allow phorm scan domains wikimedia foundation also requested opt-out scans took necessary steps block wikimedia wikipedia domains processed phorm system 16th month july 2009 nationwide building society confirmed would prevent phorm scanning website order protect privacy customers metrofi american municipal wireless network provider linked phorm ceased operations 2008 three isps linked phorm changed clarified plans since first signing company response customer concerns talktalk said implementation would opt-in opposed bt opt-out n't opt traffic split avoid contact webwise phorm server july 2009 company confirmed would implement phorm charles dunstone boss parent company told times going phorm bt whole industry interested enough business news magazine new media age reported 23 april virgin media moved away phorm expected sign deal another company named audience science bt would meet advertising companies gain isp calls general market intelligence phorm nma called moves shift strategy two media companies day later magazine said companies relationships phorm actually remain unchanged although virgin media reported moved away phorm november 2010 uk-based isp still carry information phorm webwise system website addition phorm partners international isps oi telefónica brazil ttnet-türk telekom turkey romtelecom romania phorm announced beginning market trial south korea via london stock exchange regulatory news service rns 30 march 2009 subsequently announced via rns 21 may 2009 commenced trial 8 july 2009 phorm indicated trials proceeding expected notice 2009 interim report accounts published 14 september 2009 phorm stated nearing completion substantial market trial launched may kt largest isp south korea existence trial south korea publicised ohmynews 2 september 2009 9 september 2009 ohmynews announced trial shut 26 march 2010 phorm announced plans commercial deployment brazil may 2012 brazilian internet steering committee issued resolution recommending use phorm products internet service providers country citing privacy risks concerns phorm products would degrade quality internet services respect proposed partnership telemar known oi claim ig web portal 5 penetration market phorm clear r 400 million last year since launching ttnet subsidiary türk telecom group turkey 2012 phorm launched platform five additional isps accordingly global basis 20 million daily users phorm platform according rns number 3504c 16 january 2015 phorm moved remote cookie option whilst scaling back operations turkey phorm announced 3 october 2013 launched operationally china commenced nationwide opt-in process company announced commenced commercial operations china serving advertisements paid basis privacy concerns china hong kong growing significant developments privacy regulation could impact phorm operations mainland hong kong may 2012 mainland china passed new regulations implement measures protecting consumer privacy commercial exploitation privacy legislation arrived april 2013 publication two draft rules ministry industry information technology provisions protection personal information telecommunications provisions telecommunications internet users internet users provisions registration true identity information phone users provisions phone users along draft amendments 1993 law consumer rights laws emerging e-commerce china becomes increasingly significant part chinese economy new regulations include provisions regulating data collection smart devices discussed article published international association privacy professionals privacy tracker blog called making sense china new privacy laws hong kong office privacy commissioner personal data pcpd taken robust approach protection consumer privacy seek enforce provisions personal data privacy amendment ordinance 2012 amendment ordinance came force april 2013
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Computer security
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inter-protocol exploitation inter-protocol exploitation class security vulnerabilities takes advantage interactions two communication protocols example protocols used internet commonly discussed context hypertext transfer protocol http attack uses potential two different protocols meaningfully communicating commands data popularized 2007 publicly described research year general class attacks refers known since least 1994 see security considerations section rfc 1738 internet protocol implementations allow possibility encapsulating exploit code compromise remote program uses different protocol inter-protocol exploitation utilize inter-protocol communication establish preconditions launching inter-protocol exploit example process could negotiate initial authentication communication vulnerability password parsing inter-protocol exploitation one protocol attacks service running different protocol legacy problem specifications protocols take consideration attack type two protocols involved vulnerability termed carrier target carrier encapsulates commands and/or data target protocol used communication intended victim service inter-protocol communication successful carrier protocol encapsulate commands and/or data sufficiently meaningfully communicate target service two preconditions need met successful communication across protocols encapsulation error tolerance carrier protocol must encapsulate data commands manner target protocol understand highly likely resulting data stream induce parsing errors target protocol target protocol must sufficiently forgiving errors inter-protocol connection likely percentage communication invalid cause errors meet precondition target protocol implementation must continue processing despite errors one major points concern potential attack vector reach firewalls dmzs inter-protocol exploits transmitted http launched web browsers internal subnet important point web browser exploited conventional means javascript delivered http communicating irc protocol known examples vulnerability also demonstrated files constructed valid html code bmp image time
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Computer security
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user-mode linux user-mode linux uml enables multiple virtual linux kernel-based operating systems known guests run application within normal linux system known host guest normal application running process user space approach provides user way running multiple virtual linux machines single piece hardware offering isolation generally without affecting host environment configuration stability numerous things become possible use uml one run network services uml environment remain totally sequestered main linux system uml environment runs administrators use uml set honeypots allow one test security one computers network uml serve test debug new software without adversely affecting host system uml also used teaching research providing realistic linux networked environment high degree safety uml environments host guest kernel versions n't need match entirely possible test bleeding edge version linux user-mode system running much older kernel uml also allows kernel debugging performed one machine kernel debugging tools kgdb require two machines connected null modem cable web hosting providers offer uml-powered virtual servers lower prices true dedicated servers customer root access appears system reality one physical computer shared many people libguestfs supported uml backend since version 1.24 alternative using qemu kvm uml guest application linux binary elf originally available patch kernel versions 2.2.x host kernel version 2.2.x supported easily thread mode i.e. non-skas3 linux 2.6.0 integrated main kernel source tree method running separate kernel address space skas require host kernel patching implemented improves performance security old traced thread approach processes running uml share address space host point view leads memory inside uml protected memory management unit unlike current uml using skas buggy malicious software inside uml running non-skas host could able read memory space uml processes even uml kernel memory user-mode linux generally considered lower performance competing technologies xen openvz future work adding support x86 virtualization uml may reduce disadvantage often cited strength xen competing technology support thread-local storage tls also supported latest uml kernels xen concentrates virtualizing whole machine thus systems running xen machine really virtual machines uml host machine virtualized way guest systems true virtual machines allows uml guest direct access host filesystems hardware common map host directory e.g /uml/root → uml originally designed x86 instruction set also ported others including ia-64 powerpc
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Computer architecture
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bob o'rear robert bob o'rear former employee microsoft among group eleven early microsoft employees posed iconic company photo taken albuquerque 1978 texan degrees mathematics physics left microsoft 1993 reportedly owns cattle ranch texas net worth reported 100 million o'rear born wellington texas brought perryton rural town 3,500 people texas panhandle grandparents sharecroppers cotton farm o'rear planned physical education teacher later ended graduating university texas el paso bachelor degree mathematics went graduate school university texas austin study mathematics astrophysics 1966 trw redondo beach hired o'rear work air force spy satellite programs also wrote programs optimized trajectory minuteman missiles cold war later 1960s went work nasa helped write program determined trajectory apollo command module reentered earth atmosphere nasa command center neil armstrong landed moon later 1970s o'rear friend trw days founded company called texametrics made automated machinery manufacturing polyurethane bottle caps o'rear worked program analyzed patterns correctly manufactured caps caused incorrectly manufactured parts ejected time o'rear worked hardware software helped later joined microsoft o'rear first joined microsoft 1977 became seventh employee went work company chief mathematician project manager learned programs put together also reworked math code success ms-dos ibm pc o'rear became director international sales marketing microsoft entered agreement seattle computer products acquire marketing rights 86-dos built work intel 8086 would work ibm pc intel 8088 since chips binary compatible work began soon first prototype ibm pc received thanksgiving 1980 o'rear assigned project lead sole programmer despite difficulties hardware software communication delays ibm o'rear produced pc dos v1.0 august 1981 boot sector pc dos v1.0 floppy disk even bears name instead 'microsoft inc text subsequent versions success ms-dos ibm branding pc dos made microsoft fortune 500 company o'rear retired microsoft 1993 o'rear started ranch texas panhandle grew brother o'rear provides financing business structure brother runs operates ranch spends time family pursues hobbies including golf racquetball skiing o'rear also director several boards local businesses invests real estate development retirement joined advisory council college natural sciences university texas el paso alma mater keeps working relationship university microsoft encouraging recruit students university
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Operating systems
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valid time temporal databases valid time vt time period database fact valid modeled reality december 2011 iso/iec 9075 database language part 2 sql/foundation included clauses table definitions define application-time period tables valid-time tables valid time coined richard t. snodgrass doctoral student database table valid time often represented two extra table-columns startvt endvt time interval closed lower bound open upper bound example valid time time fact true real world example person table gets two extra fields valid-from valid-to specifying person address valid real world april 4 1975 john father proudly registered son birth official insert new entry database stating john lives smallville april 3rd notice although data inserted 4th database states information valid since 3rd official yet know john ever move better place database valid-to filled infinity ∞ resulting entry database december 27 1994 john reports new address bigtown living since august 26 1994 bigtown official change address current entry john doe database adds new one original entry person john doe smallville 3-apr-1975 ∞ updated removed since known john stopped living smallville august 26 1994 valid-to entry filled database contains two entries john doe john dies database updated current entry updated stating john live bigtown longer new entry added officials never report heaven new address database looks like
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Databases
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installer.app installer.app freeware software installer iphone created nullriver later maintained ripdev first released summer 2007 maintained summer 2009 installer allowed users install third-party applications iphone applications directory native applications kept users could install applications variety sources wi-fi umts provided software developers directly onto iphone without requiring computer users could browse lists applications inside installer find ones wanted install june 2009 ripdev dropped support installer favor developing different package manager installer named icy 2.0 firmware released framework changes present applications compiled iphone os 1.2 longer able run 2.0 therefore installer 3 n't available 2.0 vast majority users switched cydia time ripdev russian iphone development took installer project started developing installer 4.0 installer 4.0 finished added quickpwn software payload installer 4.0 gain much popularity installer 3.0 jailbreak users become accustomed using cydia may 2011 team developers called infini-dev recreated installer 4 could run ios 4 although main current repositories compatible cydia longer compatible installer ripdev put old installer repo back online since infini-dev released installer also repos like greek-iphone offer date packages installer slava karpenko announced project work installer 5 slava karpenko revealed infini dev project dropped infini-dev took moved project apptapp team name currently working installer 5 developers working project release date tbd although public beta released july 3 2019
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Computer security
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transaction time temporal databases transaction time tt time fact stored database considered true december 2011 iso/iec 9075 database language part 2 sql/foundation included clauses table definitions define system-versioned tables transaction-time tables database table transaction interval often represented interval allowing system remove entries using two table-columns starttt endtt time interval closed lower bound open upper bound ending transaction time unknown may considered changed academic researchers rdbms represented changed largest timestamp supported keyword forever convention technically precise term coined richard t. snodgrass doctoral student
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Databases
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xain 'd sleena main character xain galactic bounty-hunter must defeat evil forces oppress five different planets player select order play various planets 'official sequence play u.s. version game released 'solar warrior version goes set sequence instead choose planets planet played right horizontal vertical scrolling shooting enemies dodging natural hazards xain crouch double crouch prone jump double jump planets player need kill sub-boss resume certain enemies carry powerup changes default laser gun different weapon different weapons cycled powerups include laser-grenade gun 2-way gun spreadfire gun strong bullet gun respective damage directional firing capabilities end planet player goes battle boss defeated player plants bomb boss base ten seconds escape starship next half planet stage interlude stage player must battle waves enemy ships heading next planet three planets battle asteroid field giant mothership five planets liberated player play longer final stage gigantic metallic fortress facing bosses previously met five planets fighting bosses stage optional halfway stage player plants bomb fortress core 60 seconds reach exit hangar jump starship giving commodore 64 port score 499 points ace compared game firebird game crosswize.. games machine gave atari st commodore 64 zx spectrum ports scores 70 77 86 respectively
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Computer architecture
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soap attachments api java soap attachments api java saaj provides standard way send xml documents internet java platform saaj enables developers produce consume messages conforming soap 1.1 1.2 specifications soap attachments note used alternative jax-rpc jax-ws soap simple object access protocol created mohsen al-ghosein dave winer bob atkinson box 1998 help microsoft
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Programming language topics
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macintosh ii macintosh ii personal computer designed manufactured sold apple computer inc. march 1987 january 1990 first model macintosh ii family first macintosh support color display first introduced basic system 20 mb drive monitor cost 13-inch color monitor 8-bit display card price around price placed competition workstations silicon graphics sun microsystems hewlett-packard macintosh ii designed hardware engineers michael dhuey computer brian berkeley monitor industrial designer hartmut esslinger case eighteen months introduction macintosh ii updated powerful cpu sold macintosh iix early 1989 compact macintosh iicx introduced price similar original macintosh ii beginning 1990 sales stopped altogether motherboard upgrades turn macintosh ii iix macintosh iifx offered apple two common criticisms macintosh introduction 1984 closed architecture lack color rumors color macintosh began almost immediately macintosh ii project begun dhuey berkeley 1985 without knowledge apple co-founder macintosh division head steve jobs opposed features like expansion slots color basis former complicated user experience latter conform wysiwyg since color printers common instead wanted higher-resolution monochrome displays macintosh initially referred little big mac macintosh ii codenamed milwaukee dhuey hometown later went series new names including reno becks cabernet uzi paris jean-louis gassée apple products manager protected semi-clandestine project cancellation jobs fired apple september 1985 project could proceed openly macintosh ii introduced appleworld 1987 conference los angeles low-volume initial shipments starting two months later retailing us 5,498 macintosh ii first modular macintosh model called came horizontal desktop case like many ibm pc compatibles time previous macintosh computers used all-in-one design built-in black-and-white crt macintosh ii drive bays internal hard disk originally 40 mb 80 mb optional second floppy disk drive along macintosh se first macintosh computer use apple desktop bus adb introduced apple iigs keyboard mouse interface primary improvement macintosh ii color quickdraw rom color version graphics language heart machine among many innovations color quickdraw ability handle display size 8-bit color depth multiple monitors color quickdraw included macintosh ii rom relied new 68020 instructions earlier macintoshes could upgraded display color september 1988 shortly introduction macintosh iix apple increased list price macintosh ii 20 cpu macintosh ii built around motorola 68020 processor operating 16 mhz teamed motorola 68881 floating point unit machine shipped socket mmu apple hmmu chip vlsi vi475 chip installed implement virtual memory instead translated 24-bit addresses 32-bit addresses mac os would 32-bit clean system 7 memory standard memory 1 megabyte expandable 8 mb mac ii eight 30-pin simms memory installed groups four called bank bank b original macintosh ii pmmu default relied memory controller hardware map installed memory contiguous address space hardware restriction address space dedicated bank must larger bank b though memory controller designed support 16mb 30-pin simms 128mb ram original macintosh ii roms problems limiting amount ram installed 8mb macintosh iix roms also shipped fdhd upgrade fixed problem though still 32-bit memory manager boot 32-bit addressing mode mac os without assistance mode32 mode32 contained workaround allowed larger simms put bank b pmmu installed case roms boot think computer 8mb less ram mode32 reprograms memory controller dedicate address space bank allowing additional memory bank b accessed since makes physical address space discontiguous pmmu used remap address space contiguous block graphics macintosh ii includes graphics card supports true-color 16.7 million color palette available two configurations 4-bit 8-bit 4-bit model supports 16 colors 640×480 display 256 colors 8-bit video 512×384 display means vram 256 kb 8-bit model supports 256-color video 640×480 display means vram 512 kb size optional ram upgrade requiring 120ns dip chips 4-bit version supports 640×480 8-bit color video card include hardware acceleration drawing operations display apple offered choice two displays 12 black white unit expensive 13 high-resolution color display based sony trinitron technology one display could attached computer objects could easily dragged one screen next third-party displays quickly became available los angeles times reviewer called color spectacular operating system user interface remained black white even color monitors exception apple logo appeared rainbow color storage 5.25-inch 40 mb internal scsi hard disk optional second internal 800 kilobyte 3.5-inch floppy disk drive expansion six nubus slots available expansion least one used graphics card mac ii onboard graphics chipset os n't support headless booting possible connect many six displays macintosh ii filling nubus slots graphics cards another option expansion included mac286 included intel 80286 chip could used ms-dos compatibility original roms macintosh ii contained bug prevented system recognizing one megabyte memory address space nubus card every macintosh ii manufactured approximately november 1987 defect happened slot manager 32-bit clean apple offered well-publicized recall faulty roms released program test whether particular macintosh ii defect result rare find macintosh ii original roms accessories macintosh ii macintosh se first apple computers since apple sold without keyboard instead customer offered choice new adb apple keyboard apple extended keyboard separate purchase dealers could bundle third-party keyboard attempt upsell customer expensive higher-profit extended keyboard audio macintosh ii first macintosh chimes death accompany sad mac logo whenever serious hardware error occurred new extensions featured macintosh ii time a/rose sound manager macintosh ii offered three configurations systems included mouse single 800 kb 3.5-inch floppy disk drive 68551 pmmu available option
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Computer architecture
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bit slicing bit slicing technique constructing processor modules processors smaller bit width purpose increasing word length theory make arbitrary n-bit cpu component modules processes one bit field slice operand grouped processing components would capability process chosen full word-length particular software design bit slicing less died due advent microprocessor recently used alus quantum computers used software technique e.g x86 cpus cryptography bit slice processors usually include arithmetic logic unit alu 1 2 4 8 16 bits control lines including carry overflow signals internal processor non-bitsliced cpu designs example two 4-bit alu chips could arranged side side control lines form 8-bit alu result need power two e.g three 1-bit make 3-bit alu thus 3-bit n-bit cpu 3-bit cpu higher odd-number bits n't manufactured sold volume four 4-bit alu chips could used build 16-bit alu would take eight chips build 32-bit word alu designer could add many slices required manipulate increasingly longer word lengths microsequencer control rom would used execute logic provide data control signals regulate function component alus known bit-slice microprocessor modules bit slicing although called time also used computers large scale integrated circuits lsi predecessor today vlsi very-large-scale integration circuits first bit-sliced machine edsac 2 built university cambridge mathematical laboratory 1956–1958 prior mid-1970s late 1980s debate much bus width necessary given computer system make function silicon chip technology parts much expensive today using multiple simpler thus less expensive alus seen way increase computing power cost effective manner 32-bit architecture microprocessors discussed time production univac 1100 series mainframes one oldest series originating 1950s 36-bit architecture 1100/60 introduced 1979 used nine motorola mc10800 4-bit alu chips implement needed word width using modern integrated circuits time 16-bit processors common expensive 8-bit processors z80 widely used nascent home computer market combining components produce bit slice products allowed engineers students create powerful complex computers reasonable cost using off-the-shelf components could custom-configured complexities creating new computer architecture greatly reduced details alu already specified debugged main advantage bit slicing made economically possible smaller processors use bipolar transistors switch much faster nmos cmos transistors allowed much higher clock rates speed needed example dsp functions matrix transformation xerox alto combination flexibility speed discrete cpus able deliver recent times term bit slicing re-coined matthew kwan refer technique using general purpose cpu implement multiple parallel simple virtual machines using general logic instructions perform single instruction multiple data simd operations technique also known simd within register swar initially reference eli biham 1997 paper fast new des implementation software achieved significant gains performance des using method simplify circuit structure reduce hardware cost quantum computers proposed run mips32 instruction set 50 ghz superconducting 4-bit bit-slice arithmetic logic unit alu 32-bit rapid single-flux-quantum microprocessors demonstrated
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Computer architecture
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powerpc 400 powerpc 400 family line 32-bit embedded risc processor cores based powerpc power isa instruction set architectures cores designed fit inside specialized applications ranging system-on-a-chip soc microcontrollers network appliances application-specific integrated circuits asics field-programmable gate arrays fpgas set-top boxes storage devices supercomputers applied micro circuits corporation amcc bought assets concerning 400 family cores ibm april 2004 227 million market processors name ibm continues evolving cores supplying design foundry services around cores several cores also available licensing oems ibm synopsys introduced 1994 powerpc 403 one first powerpc processors first one targeted strictly embedded market compared powerpc processors era powerpc 601 powerpc 603 powerpc 604 low end lacking memory management unit mmu floating point unit fpu instance core offered custom chips pre packaged versions including versions mmu speeds ranging 20 80 mhz powerpc 403 used among appliances thin clients set-top boxes raid-controllers network switches printers first tivo used 54 mhz powerpc 403gcx amcc acquired design 403 ibm 2004 chosen market instead focusing 405 440 cores 403 popular also high performance costly applications 1996 ibm released bare bones powerpc core called powerpc 401 single issue three-stage pipeline mmu dma 2 kb instruction 1 kb data l1 caches design contained 85,000 transistors operated 100 mhz drawing 0.1 w less applications using 401 core range set-top boxes telecom switches printers fax machines powerpc 405 released 1998 designed price performance sensitive low-end embedded system-on-a-chip soc designs five-stage pipeline separate 16 kb instruction data l1 caches coreconnect bus auxiliary processing unit apu interface expandability supports clock rates exceeding 400 mhz 405 core adheres current power isa v.2.03 using book iii-e specification amcc ibm developing marketing processors using 405 cores ibm synopsys also offers fully synthesizable core ibm announced plans make specifications powerpc 405 core freely available academic research community powerpc-405-based applications include digital cameras modems set-top boxes ibm stb04xxx processors cellphones gps-devices printers fax machines network cards network switches storage devices service processors servers two 405 cores used xilinx virtex-ii pro virtex-4 fpgas 2004 hifn bought ibm powernp network processors uses 405 cores introduced 1999 powerpc 440 first powerpc core ibm include book e extension powerpc specification also included coreconnect bus technology designed interface parts inside powerpc based system-on-a-chip soc device high-performance core separate 32 kb instruction data l1 caches seven-stage out-of-order dual-issue pipeline supporting speeds 800 mhz l2 caches 256 kb core lacks floating point unit fpu associated four-stage fpu included using apu auxiliary processing unit interface 440 core adheres power isa v.2.03 using book iii-e specification xilinx currently incorporates one two cores depending member family virtex-5 fxt fpga amcc ibm developing marketing stand alone processors using 440 cores ibm synopsys also offers fully synthesized cores processing core blue gene/p supercomputer designed manufactured ibm similar powerpc 440 details disclosed introduced 2006 460 cores similar 440 reach 1.4 ghz developed multi-core applications mind 24 additional digital signal processing dsp instructions cores designed low-power high performance 464-h90 expected draw 0.53 w 1 ghz 460 core adheres power isa v.2.03 using book iii-e specification 470 embedded customizable core adhering power isa v2.05 book iii-e designed ibm together lsi implemented powerpc 476fp 2009 476fp core 32/32 kb l1 cache dual integer units simd capable double precision fpu handles dsp instructions emitting 1.6 w 1.6 ghz 45 nm fabrication process 9 stage order 5-issue pipeline handles speeds 2 ghz supports plb6 bus 1 mb l2 cache 16 cores smp configurations
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Computer architecture
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linguatec linguatec sprachtechnologien gmbh language technology provider specialized field machine translation speech synthesis speech recognition linguatec founded munich 1996 headquarters pasing linguatec european information society technologies prize three times website using online service voice reader web information read every language means text-to-speech function
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Computational linguistics
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lynne jolitz lynne greer jolitz born june 30 1961 figure free software founded many startups silicon valley husband william lynne jolitz probably famous work pioneering open source operating systems 386bsd husband founded startup companies involve workstations companies internet multimedia lynne also noted author authority operating systems networking issues lynne internet news media commentator discussing events computer industry wrote frequently byte also holds patents internet technologies semiconductor memory innovations writes technical papers articles currently adviser coolclip network internet startup uses server-based video production engine lynne originally designed tested university california berkeley lynne appeared oracle e-business network presented geek week award years work high-speed networking operating systems design lynne also appeared dvorak ’ realcomputing discussing impact internet broadband received alumni award physics department berkeley work alumni outreach department also active women ’ entrepreneur technology networking groups mentoring girls science technology husband reside los gatos california children rebecca benjamin sarah
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Operating systems
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signal protocol signal protocol formerly known textsecure protocol non-federated cryptographic protocol used provide end-to-end encryption voice calls video calls instant messaging conversations protocol developed open whisper systems 2013 first introduced open-source textsecure app later became signal several closed-source applications claim implemented protocol whatsapp said encrypt conversations billion people worldwide facebook messenger also say offer protocol optional secret conversations skype private conversations protocol combines double ratchet algorithm prekeys triple elliptic-curve diffie–hellman 3-dh handshake uses curve25519 aes-256 hmac-sha256 primitives signal protocol development started trevor perrin moxie marlinspike open whisper systems 2013 first version protocol textsecure v1 based off-the-record messaging otr 24 february 2014 open whisper systems introduced textsecure v2 migrated axolotl ratchet design axolotl ratchet based ephemeral key exchange introduced otr combines symmetric-key ratchet modeled silent circle instant messaging protocol scimp brought support asynchronous communication offline messages major new feature well better resilience distorted order messages simpler support conversations multiple participants axolotl ratchet named critically endangered aquatic salamander axolotl extraordinary self-healing capabilities developers refer algorithm self-healing automatically disables attacker accessing cleartext later messages compromised session key third version protocol textsecure v3 made changes cryptographic primitives wire protocol october 2014 researchers ruhr university bochum published analysis textsecure v3 among findings presented unknown key-share attack protocol general found secure march 2016 developers renamed protocol signal protocol also renamed axolotl ratchet double ratchet algorithm better differentiate ratchet full protocol used name axolotl referring full protocol signal protocol based textsecure v3 additional cryptographic changes october 2016 researchers uk university oxford australia queensland university technology canada mcmaster university published formal analysis protocol concluded protocol cryptographically sound protocol provides confidentiality integrity authentication participant consistency destination validation forward secrecy post-compromise security aka future secrecy causality preservation message unlinkability message repudiation participation repudiation asynchronicity provide anonymity preservation requires servers relaying messages storing public key material signal protocol also supports end-to-end encrypted group chats group chat protocol combination pairwise double ratchet multicast encryption addition properties provided one-to-one protocol group chat protocol provides speaker consistency out-of-order resilience dropped message resilience computational equality trust equality subgroup messaging well contractible expandable membership authentication users manually compare public key fingerprints outside channel makes possible users verify identities avoid man-in-the-middle attack implementation also choose employ trust first use mechanism order notify users correspondent key changes signal protocol prevent company retaining information users communicate therefore differences messaging service providers choose handle information signal privacy policy states recipients identifiers kept signal servers long necessary order transmit message june 2016 moxie marlinspike told intercept closest piece information metadata signal server stores last time user connected server precision information reduced day rather hour minute second october 2018 signal messenger announced implemented sealed sender feature signal reduces amount metadata signal servers access concealing sender identifier sender identity conveyed recipient message encrypted key server done automatically sender recipient contacts access signal profile users also enable option receive sealed sender messages non-contacts people access signal profile contemporaneous wiretap user device and/or signal servers may still reveal device ip address accessed signal server send receive messages certain times open whisper systems first introduced protocol textsecure app later merged encrypted voice calling application called redphone textsecure app renamed signal redphone used zrtp encrypt calls march 2017 signal transitioned new webrtc-based calling system also introduced ability make video calls signal new calling system uses signal protocol end-to-end encryption november 2014 open whisper systems announced partnership whatsapp provide end-to-end encryption incorporating signal protocol whatsapp client platform open whisper systems said already incorporated protocol latest whatsapp client android support clients group/media messages key verification would coming soon april 5 2016 whatsapp open whisper systems announced finished adding end-to-end encryption every form communication whatsapp users could verify keys february 2017 whatsapp announced new feature whatsapp status uses signal protocol secure contents september 2015 g data software launched new messaging app called secure chat used signal protocol g data discontinued service may 2018 september 2016 google launched new messaging app called allo featured optional incognito mode used signal protocol end-to-end encryption march 2019 google discontinued allo favor messages app android october 2016 facebook deployed optional mode called secret conversations facebook messenger provides end-to-end encryption using implementation signal protocol january 2018 open whisper systems microsoft announced addition signal protocol support optional skype mode called private conversations signal protocol influence cryptographic protocols may 2016 viber said encryption protocol custom implementation uses concepts signal protocol forsta developers said app uses custom implementation signal protocol double ratchet algorithm introduced part signal protocol also adopted protocols omemo xmpp extension protocol xep introduced conversations messaging app approved xmpp standards foundation xsf december 2016 xep-0384 matrix open communications protocol includes olm library provides optional end-to-end encryption room-by-room basis via double ratchet algorithm implementation developers wire said app uses custom implementation double ratchet algorithm signal messenger maintains following signal protocol libraries github
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Internet protocols
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finalizer computer science finalizer finalize method special method performs finalization generally form cleanup finalizer executed object destruction prior object deallocated complementary initializer executed object creation following allocation finalizers strongly discouraged due difficulty proper use complexity add alternatives suggested instead primarily dispose pattern – see problems finalizers term finalizer primarily used object-oriented functional languages use garbage collection archetype smalltalk contrasted destructor method called finalization languages deterministic object lifetimes archetypically c++ generally exclusive – language either finalizers garbage collected destructors deterministic rare cases language may c++/cli case reference counting instead tracing garbage collection terminology varies technical usage finalizer may also used refer destructors also perform finalization subtler distinctions drawn – see terminology term final also used indicate class inherited unrelated terminology finalizer finalization versus destructor destruction varies authors sometimes unclear common usage destructor method called deterministically object destruction archetype c++ destructors finalizer called non-deterministically garbage collector archetype java codice_1 methods languages implement garbage collection via reference counting terminology varies languages objective-c perl using destructor languages python using finalizer per spec python garbage collected reference cpython implementation uses reference counting reflects fact reference counting results semi-deterministic object lifetime objects part cycle objects destroyed deterministically reference count drops zero objects part cycle destroyed non-deterministically part separate form garbage collection certain narrow technical usage constructor destructor language-level terms meaning methods defined class initializer finalizer implementation-level terms meaning methods called object creation destruction thus example original specification c language referred destructors even though c garbage-collected specification common language infrastructure cli implementation runtime environment common language runtime clr referred finalizers reflected c language committee notes read part c compiler compiles destructors ... probably instance finalizer terminology confusing thus recent versions c spec refer language-level method finalizers another language make terminology distinction d. although classes garbage collected cleanup functions called destructors finalization primarily used cleanup release memory resources deallocate memory allocated via manual memory management clear references reference counting used decrement reference counts release resources particularly resource acquisition initialization raii idiom unregister object amount finalization varies significantly languages extensive finalization c++ manual memory management reference counting deterministic object lifetimes often finalization java non-deterministic object lifetimes often implemented tracing garbage collector also possible little explicit user-specified finalization significant implicit finalization performed compiler interpreter runtime common case automatic reference counting cpython reference implementation python automatic reference counting apple implementation objective-c automatically break references finalization finalizer include arbitrary code particularly complex use automatically return object object pool memory deallocation finalization common languages like c++ manual memory management standard also occurs managed languages memory allocated outside managed heap externally language java occurs java native interface jni codice_2 objects new i/o nio latter cause problems due garbage collector able track external resources collected aggressively enough cause out-of-memory errors due exhausting unmanaged memory – avoided treating native memory resource using dispose pattern discussed finalizers generally much less necessary much less used destructors much less necessary garbage collection automates memory management much less used generally executed deterministically – may called timely manner even execution environment predicted – thus cleanup must done deterministic way must instead done method frequently manually via dispose pattern notably java python guarantee finalizers ever called thus relied cleanup due lack programmer control execution usually recommended avoid finalizers trivial operations particular operations often performed destructors usually appropriate finalizers common anti-pattern write finalizers destructors unnecessary ineffectual due differences finalizers destructors particularly common among c++ programmers destructors heavily used idiomatic c++ following resource acquisition initialization raii idiom programming languages use finalizers include c++/cli c clean go java python syntax varies significantly language java finalizer method called codice_1 overrides codice_4 method python finalizer method called codice_5 perl finalizer method called codice_6 c finalizer called destructor earlier versions standard method whose name class name codice_7 prefixed codice_8 – syntax c++ destructor methods originally called destructors analogy c++ despite different behavior renamed finalizers due confusion caused c++/cli destructors finalizers destructor method whose name class name codice_7 prefixed codice_8 c++ finalizer method whose name class name codice_11 prefixed codice_12 go finalizers applied single pointer calling codice_13 function standard library finalizer called object garbage collected – object become garbage unreachable memory deallocated finalization occurs non-deterministically discretion garbage collector might never occur contrasts destructors called deterministically soon object longer use always called except case uncontrolled program termination finalizers frequently instance methods due needing object-specific operations garbage collector must also account possibility object resurrection commonly done first executing finalizers checking whether objects resurrected aborting destruction additional check potentially expensive – simple implementation re-checks garbage even single object finalizer – thus slows complicates garbage collection reason objects finalizers may collected less frequently objects without finalizers certain cycles exacerbating problems caused relying prompt finalization resource leaks object resurrected question whether finalizer called next destroyed – unlike destructors finalizers potentially called multiple times finalizers called resurrected objects objects may repeatedly resurrect indestructible occurs cpython implementation python prior python 3.4 clr languages c avoid many languages including java objective-c least recent apple implementations python python 3.4 objects finalized requires tracking object finalized yet cases notably clr languages like c finalization tracked separately objects objects repeatedly registered deregistered finalization finalizers cause significant number problems thus strongly discouraged number authorities problems include finalizers may fail run due object remaining reachable beyond expected garbage either due programming errors due unexpected reachability example python catches exception exception caught interactive mode keeps reference stack frame exception raised keeps objects referenced stack frame alive finalizers superclass also slow garbage collection subclass finalizer potentially refer fields subclass thus field garbage collected following cycle finalizer run avoided using composition inheritance common anti-pattern use finalizers release resources analogy resource acquisition initialization raii idiom c++ acquire resource initializer constructor release finalizer destructor work number reasons basically finalizers may never called even called may called timely manner – thus using finalizers release resources generally cause resource leaks finalizers called prescribed order resources often need released specific order frequently opposite order acquired also finalizers called discretion garbage collector often called managed memory pressure little managed memory available regardless resource pressure – scarce resources held garbage plenty managed memory available garbage collection may occur thus reclaiming resources thus instead using finalizers automatic resource management garbage-collected languages one instead must manually manage resources generally using dispose pattern case resources may still acquired initializer called explicitly object instantiation released dispose method dispose method may called explicitly implicitly language constructs c codice_14 java codice_15-with-resources python codice_16 however certain cases dispose pattern finalizers used releasing resources primarily found clr languages c finalization used backup disposal resource acquired acquiring object queued finalization resource released object destruction even resource released manual disposal languages deterministic object lifetimes notably c++ resource management frequently done tying resource possession lifetime object lifetime acquiring resources initialization releasing finalization known resource acquisition initialization raii ensures resource possession class invariant resources released promptly object destroyed however languages non-deterministic object lifetimes – include major languages garbage collection c java python – work finalization may timely may happen thus resources may released long time even causing resource leaks languages resources instead generally managed manually via dispose pattern resources may still acquired initialization released calling codice_17 method nevertheless using finalization releasing resources languages common anti-pattern forgetting call codice_17 still cause resource leak cases techniques combined using explicit dispose method also releasing still-held resources finalization backup commonly found c implemented registering object finalization whenever resource acquired suppressing finalization whenever resource released user-specified finalizers allowed possible finalization cause object resurrection finalizers run arbitrary code may create references live objects objects destroyed languages without garbage collection severe bug causes dangling references memory safety violations languages garbage collection prevented garbage collector commonly adding another step garbage collection running user-specified finalizers check resurrection complicates slows garbage collection object resurrection means object may destroyed pathological cases object always resurrect finalization making indestructible prevent languages like java python python 3.4 finalize objects finalize resurrected objects concretely done tracking object finalized object-by-object basis objective-c also tracks finalization least recent apple versions similar reasons treating resurrection bug different approach used .net framework notably c visual basic .net finalization tracked queue rather object case user-specified finalizer provided default object finalized queued finalization creation dequeued finalized changed via calling codice_19 module finalization prevented calling codice_20 dequeues object reactivated calling codice_21 enqueues object particularly used using finalization resource management supplement dispose pattern implementing object pool finalization formally complementary initialization – initialization occurs start lifetime finalization end – differs significantly practice variables objects initialized primarily assign values general objects finalized general need clear values – memory simply deallocated reclaimed operating system beyond assigning initial values initialization primarily used acquire resources register object service like event handler actions symmetric release unregister actions symmetrically handled finalizer done raii however many languages notably garbage collection object lifetime asymmetric object creation happens deterministically explicit point code object destruction happens non-deterministically unspecified environment discretion garbage collector asymmetry means finalization effectively used complement initialization happen timely manner specified order specified environment symmetry partially restored also disposing object explicit point case disposal destruction happen point object may disposed still alive state weakens class invariants complicates use variables generally initialized start lifetime finalized end lifetime – though variable object value object may finalized cases variables also finalized gcc extensions allow finalization variables reflected naming finalization codice_22 construct fulfill similar purposes performing final action generally cleaning something else finished differ occur – codice_22 clause executed program execution leaves body associated codice_15 clause – occurs stack unwind thus stack pending codice_22 clauses order – finalization occurs object destroyed happens depending memory management method general simply set objects awaiting finalization – often heap – need happen specific order however cases coincide c++ object destruction deterministic behavior codice_22 clause produced local variable object value whose scope block corresponds body codice_15 clause – object finalized destructed execution exits scope exactly codice_22 clause reason c++ codice_22 construct – difference finalization defined class definition destructor method rather call site codice_22 clause conversely case codice_22 clause coroutine like python generator coroutine may never terminate – ever yielding – thus ordinary execution codice_22 clause never executed one interprets instances coroutine objects codice_22 clause considered finalizer object thus executed instance garbage collected python terminology definition coroutine generator function instance generator iterator thus codice_22 clause generator function becomes finalizer generator iterators instantiated function notion finalization separate step object destruction dates analogy earlier distinction initialization object construction literature prior point used destruction process distinguishing finalization deallocation programming languages dating period like c++ perl use term destruction terms finalize finalization also used influential book design patterns 1994 introduction java 1995 contained codice_1 methods popularized term associated garbage collection languages point generally make distinction use term finalization particularly context garbage collection
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Operating systems
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john bridges software developer john bridges co-author computer program pcpaint primary developer program grasp microtex industries doug wolfgram also sole author glpro aftergrasp article entitled differential image compression published february 1991 issue dr. dobb journal 1980 bridges started programming career nyu institute reconstructive plastic surgery summer intern working sophisticated programmable vector graphics systems wrote editing tools also updated debugged software used early 3d x-ray scanning research 1981-85 bridges wrote ram disk drivers utilities cracking software task switching software memory test diagnostics abacus maker large memory cards apple ii 1982 started working classroom consortia media inc. educational software company developing writing apple ibm graphics libraries tools software tenure created drawing program called superdraw ccm wrote core graphics code would later become pcpaint well develop grasp gl library format 1984 bridges developed first version pcpaint doug wolfgram mouse systems pcpaint first ibm pc-based mouse driven gui paint program company purchased exclusive rights pcpaint john continued development 1990 1985 bridges pcpaint code doug slideshow program morphed new program grasp grasp first multimedia animation program ibm pc created grasp gl library format grasp originally released shareware doug company microtex industries however version 2.0 sold commercially paul mace software doug sold shares pcpaint grasp bridges 1990 bridges work grasp continued 1994 terminated contract paul mace software bridges work grasp included several toolsets add-ons pictor paint artools hrfe high res flic enhancement pc speaker sound code caused paul mace software threatened lawsuit realsound use frequency modulation upon realsound held patent stripped-down version grasp 4.0 also included copies philip shaddock multimedia creations hands-on workshop exploring animation sound 1987 bridges released vidspeed freeware program tests speed graphics cards measuring throughput writing constant pixel data video memory bus graphics modes vidspeed well received community recommended least two books patrick killelea web performance tuning stephen j. bigelow bigelow computer repair toolkit though bigelow expresses concern support updates 1986-87 bridges authored project ibm multimedia lab played back full color video 1/4 size window new ibm model 30 8 mhz 8086 cpu new mcga 320x200 256-color video mode play full color video early date dos history smoothly one slowest low-end ibm ps/2 models sold ibm applied patent algorithms developed though filed name project manager ibm algorithms later published article bridges entitled differential image compression first appeared dr. dobb journal february 1991 later reprinted magazine july 2001 along james h. sylvester 1993 article differential compression algorithms adapts bridges algorithms generalized data graphics ibm project came imagetools 1987 collection high color 15bit 24bit 32bit vga/ega image conversion scaling tools sold metacreations corp./harvard systems corp hsc software 1988 bridges authored freeware image viewer program called picem image viewers time commercial picem also allowed user adjust images brightness contrast save image viewed formats including bsave graphics image format picem became popular enough microsoft offered tech help using conjunction quickbasic also 1988 bridges released vgakit vgakit svga programming kit freeware vgakit open source library accessing extended graphics modes dos standardized vesa vbe arrived used several open closed source projects developer univbe program extended video cards bios become compatible new vesa vbe said bridges provided information without univbe would never gotten started whole pc graphics community deeply debt author michael abrash 1997 book graphics programming black book says little ddj dr. dobb journal columns published mode x although bridges widely distributed code number undocumented 256-color resolutions ’ like acknowledge influence code mode set routine presented chapter 47 codes abrash refers mode x 360x480 256-color mode codes bridges included vgakit worked vga svgas abrash ddj articles published circa 1991 compiled gpbb grasp 3.5 released included bridges newest version pcpaint pictor paint version 4.0 included bridges artools collection image manipulation tools included early morphing utility tracked points source destination images creating in-between frames 1995 bridges created glpro ims newest incarnation bridges ideas behind grasp updated windows 2000 glpro became property gmedia plc closed 2001 bridges stopped glpro work time stripped version glpro included conrad r. brandt book glpro foundations 2000 2002 bridges started work new program aftergrasp designed backwards compatible glpro work still continuing project pictor pic image format image file format developed bridges pcpaint also native file format grasp glpro first widely accepted dos imaging standard
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Programming language topics
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christine o'keefe christine margaret o'keefe australian mathematician computer scientist whose research included work finite geometry information security data privacy researcher csiro lead author 2017 report office australian information commissioner best practices de-identification personally identifying data o'keefe bachelor degree university adelaide initially intending study medicine earning first-class honours mathematics 1982 returned adelaide doctoral study 1985 completed ph.d. 1988 dissertation concerning formula_1-spreads formula_2 supervised rey casse lecturer research fellow university western australia 1999 2001 returned university adelaide adelaide worked lecturer senior lecturer queen elizabeth ii fellow senior research fellow research interests shifted finite geometry information security effect shift moved 2000 adelaide csiro csiro founded information security privacy group 2002 became head health informatics group 2004 became theme leader health data information 2006 strategic operations director preventative health national research 2008 studied mba australian national university finishing 2008 became director population health research network centre professor health sciences curtin university 2009 2010 returning csiro science leader privacy confidentiality csiro department mathematics informatics statistics o'keefe fellow institute combinatorics applications since 1991 1996 o'keefe hall medal institute combinatorics applications work finite geometry australian mathematical society medal 2000 first woman win medal year became fellow australian mathematical society although medal citation primarily discussed o'keefe work finite geometry discovery new hyperovals included paragraph research using geometry secret sharing precursor later work information security
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Computer security
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job control unix unix unix-like operating systems job control refers control jobs shell especially interactively job shell representation process group basic job control features suspending resuming terminating processes job/process group advanced features performed sending signals job job control particular interest unix due multiprocessing distinguished job control generally frequently applied sequential execution batch processing using unix unix-like operating systems via terminal terminal emulator user initially single process running login shell tasks directory listing editing files etc easily accomplished letting program take control terminal returning control shell program exits – formally attaching standard input standard output shell reads writes terminal catching signals sent keyboard like termination signal resulting pressing however sometimes user wish carry task using terminal another purpose task running receiving input terminal said running background single task receiving input terminal foreground job control facility developed make possible allowing user start processes background send already running processes background bring background processes foreground suspend terminate processes concept job maps shell concept single shell command operating system concept possibly many processes command entails multi-process tasks come processes may create additional child processes single shell command may consist pipeline multiple communicating processes example command select lines containing text title sort alphabetically display result pager creates least three processes one one one job control allows shell control related processes one entity user issues appropriate key combination usually entire group processes gets suspended jobs managed operating system single process group job shell internal representation group defined posix job referred handle called job control job id simply used shell builtins refer job job ids begin codice_1 character codice_2 identifies job n codice_3 identifies current job job ids specified posix informal usage number may referred job number job id bash documentation refers -prefixed job id jobspec job control job ids typically used interactive use simplify referring process groups scripting pgids used instead precise robust indeed job control disabled default bash scripts job control first implemented c shell jim kulp iiasa austria making use features 4.1bsd kernel korn shell developed bell labs adopted later incorporated svr4 version bourne shell exists modern unix shells posix standard specifies two commands resuming suspended jobs background foreground respectively modeled korn shell job control commands typically shell keeps list jobs job table recall job corresponds process group consists members pipeline descendants codice_4 command list background jobs existing job table along job number job state stopped running session ends user logs exits shell terminates session leader process shell process sends sighup jobs waits process groups end terminating codice_5 command used remove jobs job table session ends child process groups sent sighup shell wait terminate thus become orphan processes may terminated operating system though often used processes adopted init kernel sets parent process init continue executing daemons alternatives prevent jobs terminated include nohup using terminal multiplexer job running foreground stopped typing suspend character ctrl-z sends terminal stop signal sigtstp process group default sigtstp causes processes receiving stop control returned shell however process register signal handler ignore sigtstp process also paused stop signal sigstop caught ignored job running foreground interrupted typing interruption character ctrl-c sends interrupt signal sigint defaults terminating process though overridden stopped job resumed background job codice_6 builtin foreground job codice_7 either case shell redirects i/o appropriately sends sigcont signal process causes operating system resume execution bash program started background job appending ampersand codice_8 command line output directed terminal potentially interleaved programs output read terminal input background process attempts read write controlling terminal sent sigttin input sigttou output signal signals stop process default may also handled ways shells often override default stop action sigttou background processes deliver output controlling terminal default bash-compatible shells codice_9 builtin codice_10 signal jobs job id well process group id – sending signal job sends whole process group jobs specified job id killed prefixing codice_1 kill send signal job however intent rid system processes signals sigkill sigterm default probably applicable
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Operating systems
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refined printing command stream refined printing command stream also known rpcs vector-based printing/duplicating control protocol designed communication microsoft windows pc clients several lines ricoh copiers drivers provided ricoh install chosen copier behave printer device size-efficiency protocol comparable pcl6 ricoh offers rpcs based drivers windows mac os extent linux drivers linux provided japanese website instead aficio called ipsio
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Programming language topics
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copyright alternatives various copyright alternatives alternative compensation systems acs proposed ways allow widespread reproduction digital copyrighted works still paying authors copyright owners works article discusses proposals involve form government intervention models street performer protocol voluntary collective licenses could arguably called alternative compensation systems although different generally less effective solving free rider problem impetus proposals come widespread use peer-to-peer file sharing networks authors argue acs simply practical response situation acs advocates go holding p2p file sharing fact greatly beneficial tax levy funded systems actually desirable tools paying artists sales coupled drm copy prevention technologies artistic freedom voucher afv proposal argues current copyright system providing state enforced monopoly leads enormous inefficiencies creates substantial enforcement problems afv proposed system individuals would allowed contribute refundable tax credit approximately 100 creative worker contribution would act voucher used support artistic creative work recipients afv contribution would turn required register government similar fashion religious charitable institutions tax-exempt status sole purpose registration would prevent fraud would evaluation quality work produced alongside registration artists would also ineligible copyright protection set period time 5 years example work contributed public domain allowed freely reproduced afv would affect creative workers ability receive funds via live performances proponents claim system could create 20 billion annually pay artists far greater currently flows copyrighted material 100 per adult voucher 500,000 writers musicians singers actors creative workers could paid 40,000 year baker also states realistic assume savings reduced expenditures copyrighted work would vastly exceed cost afv majority savings would come individuals deciding use afv supported work place copyrighted work well lower advertising costs afv material would public domain copyright enforcement demand would also decrease afv material increased assumptions made low end direct costs public copyrighted material would reduced around 20 percent high end way 60 percent time also likely savings would increase due lesser costs system brighter prospects 2010 article critical afv proposal graphic designer mark stanley writes like school vouchers flat tax pretenders afv assumes necessity state intervention tries bend liberty around strictures freedom ’ forgiving manipulation systematic restructuring copyright laws proposed afv far put practice concept paying artists donations tested success 2006 musician jeff rosenstock founded quote unquote records advertised first donation-based record label artists label make music available download free invite listeners make small donation want donations ticket sales live shows quote unquote records successfully recording music expanding number bands label past twelve years proposals included targeted levies internet connections blank cds digital media players etc many goods levied various countries existing private copying schemes income taxation optional payments users terms economic theory consumer opt regimes different universal ones depending scheme administered differences might large example default option isp subscribers pay acs surcharge could avoided filing signed commitment make unauthorised downloads p2p networks effects might quite similar scheme however unsuitable business owners maintain free internet connections incentive customers would responsibility business owner monitor customer internet use various proposals made base distribution royalties measures consumer downloading usage voting computer security issues addressed collecting data considerable privacy verifiability obstacles similar encountered internet voting may soluble hardware assistance currently available ordinary pcs practical way deploy acs short term would collect statistical samples much smaller population actual distribution royalties would likely carried copyright collecting society alternative compensation systems two significant advantages digital copyright impose artificial scarcity copyright works everyone download many songs ebooks films want economic terns acs eliminate deadweight loss copyright monopolies also avoid high technological social costs digital copyright enforcement two greatest drawbacks acses excess burden taxation collected need decide tax/levy rates use system although methods contingent valuation may help little question canada private copying levy unforeseen result temporarily creating acs kinds p2p downloading bmg v. doe dictum suggested also apply uploading dictum criticised appeal france december 2005 dadvsi amendments passed senate would created acs called global license amendments removed bill finally became law 2009 german social democratic party added proposal acs variant called cultural flat-rate party platform
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Computer security
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