GitHub is a web-based hosting service for version control using Git. It is used for computer code, it offers all of the distributed version control and source code management functionality of Git as well as adding its own features. It provides access control and several collaboration features such as bug tracking, feature requests, task management, wikis for every project. GitHub offers plans for enterprise, team and free accounts which are used to host open-source software projects; as of January 2019, GitHub offers unlimited private repositories to all plans, including free accounts. As of June 2018, GitHub reports having over 28 million users and 57 million repositories, making it the largest host of source code in the world. GitHub was developed by Chris Wanstrath, P. J. Hyett, Tom Preston-Werner and Scott Chacon using Ruby on Rails, started in February 2008; the company, GitHub, Inc. is located in San Francisco. On February 24, 2009, GitHub team members announced, in a talk at Yahoo! headquarters, that within the first year of being online, GitHub had accumulated over 46,000 public repositories, 17,000 of which were formed in the previous month alone.
At that time, about 6,200 repositories had been forked at least. On July 5, 2009, GitHub announced. On July 27, 2009, in another talk delivered at Yahoo!, Preston-Werner announced that GitHub had grown to host 90,000 unique public repositories, 12,000 having been forked at least once, for a total of 135,000 repositories. On July 25, 2010, GitHub announced. On April 20, 2011, GitHub announced. On June 2, 2011, ReadWriteWeb reported that GitHub had surpassed SourceForge and Google Code in total number of commits for the period of January to May 2011. On July 9, 2012, Peter Levine, general partner at GitHub investor Andreessen Horowitz, stated that GitHub had been growing revenue at 300% annually since 2008 "profitably nearly the entire way". On January 16, 2013, GitHub announced it had passed the 3 million users mark and was hosting more than 5 million repositories. On December 23, 2013, GitHub announced. In June 2015, GitHub opened an office in Japan, its first office outside of the U. S. On July 29, 2015, GitHub announced it had raised $250 million in funding in a round led by Sequoia Capital.
The round valued the company at $2 billion. In 2016, GitHub was ranked No. 14 on the Forbes Cloud 100 list. On February 28, 2018, GitHub fell victim to the second largest distributed denial-of-service attack in history, with incoming traffic reaching a peak of about 1.35 terabits per second. On June 4, 2018, Microsoft announced it had reached an agreement to acquire GitHub for US$7.5 billion. The purchase closed on October 26, 2018. On June 19, 2018, GitHub expanded its GitHub Education by offering free education bundles to all schools. On June 4, 2018, Microsoft announced its intent to acquire GitHub for US$7.5 billion, the deal closed on Oct. 26, 2018. GitHub will continue to operate independently as a community and business. Under Microsoft, the service will be led by Xamarin's Nat Friedman, reporting to Scott Guthrie, executive vice president of Microsoft Cloud and AI. Current CEO Chris Wanstrath will be retained as a "technical fellow" reporting to Guthrie. Microsoft had become a significant user of GitHub, using it to host open source projects and development tools such as Chakra Core, PowerShell, Visual Studio Code, has backed other open source projects such as Linux, developed Git Virtual File System—a Git extension for managing large-scale repositories.
GitHub, Inc. was a flat organization with no middle managers. Employees can choose to work on projects. However, salaries are set by the chief executive. In 2014, GitHub, Inc. introduced a layer of middle management. GitHub.com was a start-up business, which in its first years provided enough revenue to be funded by its three founders and start taking on employees. In July 2012, four years after the company was founded, Andreessen Horowitz invested $100 million in venture capital. In July 2015 GitHub raised another $250 million of venture capital in a series B round. Investors were Andreessen Horowitz, Thrive Capital and other venture capital funds; as of August 2016, GitHub was making $140 million in Annual Recurring Revenue. GitHub's m
Microsoft Windows is a group of several graphical operating system families, all of which are developed and sold by Microsoft. Each family caters to a certain sector of the computing industry. Active Windows families include Windows Embedded. Defunct Windows families include Windows Mobile and Windows Phone. Microsoft introduced an operating environment named Windows on November 20, 1985, as a graphical operating system shell for MS-DOS in response to the growing interest in graphical user interfaces. Microsoft Windows came to dominate the world's personal computer market with over 90% market share, overtaking Mac OS, introduced in 1984. Apple came to see Windows as an unfair encroachment on their innovation in GUI development as implemented on products such as the Lisa and Macintosh. On PCs, Windows is still the most popular operating system. However, in 2014, Microsoft admitted losing the majority of the overall operating system market to Android, because of the massive growth in sales of Android smartphones.
In 2014, the number of Windows devices sold was less than 25 %. This comparison however may not be relevant, as the two operating systems traditionally target different platforms. Still, numbers for server use of Windows show one third market share, similar to that for end user use; as of October 2018, the most recent version of Windows for PCs, tablets and embedded devices is Windows 10. The most recent versions for server computers is Windows Server 2019. A specialized version of Windows runs on the Xbox One video game console. Microsoft, the developer of Windows, has registered several trademarks, each of which denote a family of Windows operating systems that target a specific sector of the computing industry; as of 2014, the following Windows families are being developed: Windows NT: Started as a family of operating systems with Windows NT 3.1, an operating system for server computers and workstations. It now consists of three operating system subfamilies that are released at the same time and share the same kernel: Windows: The operating system for mainstream personal computers and smartphones.
The latest version is Windows 10. The main competitor of this family is macOS by Apple for personal computers and Android for mobile devices. Windows Server: The operating system for server computers; the latest version is Windows Server 2019. Unlike its client sibling, it has adopted a strong naming scheme; the main competitor of this family is Linux. Windows PE: A lightweight version of its Windows sibling, meant to operate as a live operating system, used for installing Windows on bare-metal computers, recovery or troubleshooting purposes; the latest version is Windows PE 10. Windows IoT: Initially, Microsoft developed Windows CE as a general-purpose operating system for every device, too resource-limited to be called a full-fledged computer. However, Windows CE was renamed Windows Embedded Compact and was folded under Windows Compact trademark which consists of Windows Embedded Industry, Windows Embedded Professional, Windows Embedded Standard, Windows Embedded Handheld and Windows Embedded Automotive.
The following Windows families are no longer being developed: Windows 9x: An operating system that targeted consumers market. Discontinued because of suboptimal performance. Microsoft now caters to the consumer market with Windows NT. Windows Mobile: The predecessor to Windows Phone, it was a mobile phone operating system; the first version was called Pocket PC 2000. The last version is Windows Mobile 6.5. Windows Phone: An operating system sold only to manufacturers of smartphones; the first version was Windows Phone 7, followed by Windows Phone 8, the last version Windows Phone 8.1. It was succeeded by Windows 10 Mobile; the term Windows collectively describes any or all of several generations of Microsoft operating system products. These products are categorized as follows: The history of Windows dates back to 1981, when Microsoft started work on a program called "Interface Manager", it was announced in November 1983 under the name "Windows", but Windows 1.0 was not released until November 1985.
Windows 1.0 was to achieved little popularity. Windows 1.0 is not a complete operating system. The shell of Windows 1.0 is a program known as the MS-DOS Executive. Components included Calculator, Cardfile, Clipboard viewer, Control Panel, Paint, Reversi and Write. Windows 1.0 does not allow overlapping windows. Instead all windows are tiled. Only modal dialog boxes may appear over other windows. Microsoft sold as included Windows Development libraries with the C development environment, which included numerous windows samples. Windows 2.0 was released in December 1987, was more popular than its predecessor. It features several improvements to the user memory management. Windows 2.03 changed the OS from tiled windows to overlapping windows. The result of this change led to Apple Computer filing a suit against Microsoft alleging infringement on Apple's copyrights. Windows 2.0
Compuware Corporation is an American software company with products aimed at the information technology departments of large businesses. The company's services include testing, development and performance management software for programs running on mainframe computer systems; the company has its headquarters in Michigan. In December 2014, Compuware was acquired by private equity firm Thoma Bravo and became a held company. In 1973, Peter Karmanos, Jr. Thomas Thewes, Allen B. Cutting established Compuware Corporation, their vision was to help people do things with computers by providing their clients with professional technical services, allowing them to focus on their own core businesses. In 1977, Compuware introduced its first software product. Designed to detect bugs and suggest corrective action in corporate IBM mainframe systems; the release of Abend-AID established a product strategy for Compuware, alleviating the peaks and valleys of revenue that occur in the services business. By 1978, Compuware opened its first remote office to service the Washington, D.
C. and Baltimore area. Compuware launched its File-AID product line. Using a request-driven interface, File-AID products help programmers and developers and find, extract, fix, load, edit and compare data; this allows developers to focus on maintaining applications that meet business needs. Compuware announced Playback, the company's first automated testing tool. Compuware moved from its Southfield location to a new corporate headquarters in Farmington Hills, Michigan. Compuware acquired its first European subsidiaries during the 1980s. Compuware launched Powerbase with Datazoom, a user-friendly, non-programmable, relational database for MS-DOS through Compuware/Power-base Systems, Inc. Throughout the 1990s, Compuware acquired several companies, building their position in the marketplace, including Centura Software, XA Systems, EcoSystems Software, Uniface development environment, Coronet, Direct Technology Limited, DRD Promark, Inc, NuMega, Data Processing Resources Corporation and the CACI Products Company.
In 1992, Compuware completed its initial public offering of stock trading on the NASDAQ under the symbol CPWR. In 1994, Compuware commenced a secondary public offering to raise cash, named Joseph A. Nathan President and Chief Operating Officer. By April 1998, Compuware had more than $800 million in sales. At the end of 1998, Compuware surpassed the US$1 billion revenue mark. In 1999, the number of Compuware employees grew prompting the company to build a new headquarters building in Campus Martius Park in Detroit, Michigan. Since 2000, Compuware has acquired Inc.. Nomex, Inc. Covisint, LLC, Inc. SteelTrace, Proxima Technology's Centauri Business Service Manager. In 2003, the company's 30th year of existence, Compuware completed construction on its new world headquarters building in downtown Detroit. On November 9, 2009 Compuware acquired Gomez, Inc. for its application performance management software. On July 6, 2011, Compuware acquired dynaTrace software. On September 25, 2013 Compuware subsidiary Covisint announced pricing of Initial Public Offering.
On January 8, 2014 Compuware announced the planned divestiture of its Changepoint, Professional Services, Uniface divisions to Marlin Equity Partners for $160 million. Compuware completed a spin-off of Covisint on October 31, 2014. In December 2014, Compuware was acquired by private equity firm Thoma Bravo, LLC. On September 2, 2014 Compuware and private equity firm Thoma Bravo, LLC, jointly announced that Compuware had entered into a definitive agreement to be acquired by Thoma Bravo for $2.5 billion. After finalizing the deal in December 2014, plans were announced to separate Compuware's remaining Mainframe and Application Performance Management business units into two distinct companies; the mainframe business unit retains the Compuware name and is focused on mainframe software. Christopher O'Malley is the current CEO. Compuware's former APM business operates independently under the new Dynatrace name with John Van Siclen operating as CEO; as a result of the privatization, Compuware stock is no longer listed on the NASDAQ.
Beginning in 2014, around the time of Thoma Bravo, LLC's acquisition, Compuware began shifting from a Waterfall development methodology to Agile development. With the release of Compuware Topaz—a solution that allows developers, data architects and other IT professionals to discover and work with mainframe and non-mainframe data in a common, intuitive manner—on January 5, 2015, Compuware has since released net-new mainframe software on a quarterly basis. In an interview with Jim Probasco of Benzinga, Compuware CEO Chris O'Malley said the company had adopted a startup mentality and that he supported an "agenda of innovation where our strategy is, every quarter like clockwork, to introduce updates to the existing base of technology as well as bringing out net new products." "We've retooled development," he added, "and gone from the traditional'waterfall' model that has 12 to 18 month development cycles quarterly with an'agile' methodology." By pursuing technology integrations and partnerships with companies focused on non-mainframe DevOps software, Compuware has allowed "CIOs to shift responsibility for mainframe applications to enterprise DevOps staff with mainstream skills using popular tools within today's mainstream culture of agility and innovation."
According to eWeek, "O'Malley said he believes that large enterprises that fail to bring Agile and DevOps best practices to their high-value COBOL applications wi
Linux is a family of free and open-source software operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991 by Linus Torvalds. Linux is packaged in a Linux distribution. Distributions include the Linux kernel and supporting system software and libraries, many of which are provided by the GNU Project. Many Linux distributions use the word "Linux" in their name, but the Free Software Foundation uses the name GNU/Linux to emphasize the importance of GNU software, causing some controversy. Popular Linux distributions include Debian and Ubuntu. Commercial distributions include SUSE Linux Enterprise Server. Desktop Linux distributions include a windowing system such as X11 or Wayland, a desktop environment such as GNOME or KDE Plasma. Distributions intended for servers may omit graphics altogether, include a solution stack such as LAMP; because Linux is redistributable, anyone may create a distribution for any purpose. Linux was developed for personal computers based on the Intel x86 architecture, but has since been ported to more platforms than any other operating system.
Linux is the leading operating system on servers and other big iron systems such as mainframe computers, the only OS used on TOP500 supercomputers. It is used by around 2.3 percent of desktop computers. The Chromebook, which runs the Linux kernel-based Chrome OS, dominates the US K–12 education market and represents nearly 20 percent of sub-$300 notebook sales in the US. Linux runs on embedded systems, i.e. devices whose operating system is built into the firmware and is tailored to the system. This includes routers, automation controls, digital video recorders, video game consoles, smartwatches. Many smartphones and tablet computers run other Linux derivatives; because of the dominance of Android on smartphones, Linux has the largest installed base of all general-purpose operating systems. Linux is one of the most prominent examples of open-source software collaboration; the source code may be used and distributed—commercially or non-commercially—by anyone under the terms of its respective licenses, such as the GNU General Public License.
The Unix operating system was conceived and implemented in 1969, at AT&T's Bell Laboratories in the United States by Ken Thompson, Dennis Ritchie, Douglas McIlroy, Joe Ossanna. First released in 1971, Unix was written in assembly language, as was common practice at the time. In a key pioneering approach in 1973, it was rewritten in the C programming language by Dennis Ritchie; the availability of a high-level language implementation of Unix made its porting to different computer platforms easier. Due to an earlier antitrust case forbidding it from entering the computer business, AT&T was required to license the operating system's source code to anyone who asked; as a result, Unix grew and became adopted by academic institutions and businesses. In 1984, AT&T divested itself of Bell Labs; the GNU Project, started in 1983 by Richard Stallman, had the goal of creating a "complete Unix-compatible software system" composed of free software. Work began in 1984. In 1985, Stallman started the Free Software Foundation and wrote the GNU General Public License in 1989.
By the early 1990s, many of the programs required in an operating system were completed, although low-level elements such as device drivers and the kernel, called GNU/Hurd, were stalled and incomplete. Linus Torvalds has stated that if the GNU kernel had been available at the time, he would not have decided to write his own. Although not released until 1992, due to legal complications, development of 386BSD, from which NetBSD, OpenBSD and FreeBSD descended, predated that of Linux. Torvalds has stated that if 386BSD had been available at the time, he would not have created Linux. MINIX was created by Andrew S. Tanenbaum, a computer science professor, released in 1987 as a minimal Unix-like operating system targeted at students and others who wanted to learn the operating system principles. Although the complete source code of MINIX was available, the licensing terms prevented it from being free software until the licensing changed in April 2000. In 1991, while attending the University of Helsinki, Torvalds became curious about operating systems.
Frustrated by the licensing of MINIX, which at the time limited it to educational use only, he began to work on his own operating system kernel, which became the Linux kernel. Torvalds began the development of the Linux kernel on MINIX and applications written for MINIX were used on Linux. Linux matured and further Linux kernel development took place on Linux systems. GNU applications replaced all MINIX components, because it was advantageous to use the available code from the GNU Project with the fledgling operating system. Torvalds initiated a switch from his original license, which prohibited commercial redistribution, to the GNU GPL. Developers worked to integrate GNU components with the Linux kernel, making a functional and free operating system. Linus Torvalds had wanted to call his invention "Freax", a portmant
Allusion is a figure of speech, in which an object or circumstance from unrelated context is referred to covertly or indirectly. It is left to the audience to make the direct connection. Where the connection is directly and explicitly stated by the author, it is instead termed a reference. In the arts, a literary allusion puts the alluded text in a new context under which it assumes new meanings and denotations, it is not possible to predetermine the nature of all the new meanings and inter-textual patterns that an allusion will generate. Literary allusion is related to parody and pastiche, which are "text-linking" literary devices. In a wider, more informal context, an allusion is a passing or casually short statement indicating broader meaning, it is an incidental mention of something, either directly or by implication, such as "In the stock market, he met his Waterloo." In the most traditional sense, allusion is a literary term, though the word has come to encompass indirect references to any source, including allusions in film or the visual arts.
In literature, allusions are used to link concepts that the reader has knowledge of, with concepts discussed in the story. In the field of film criticism, a film-maker's intentionally unspoken visual reference to another film is called an homage, it may be sensed that real events have allusive overtones, when a previous event is inescapably recalled by a current one. "Allusion is bound up with a vital and perennial topic in literary theory, the place of authorial intention in interpretation", William Irwin observed, in asking "What is an allusion?"Without the hearer or reader's comprehending the author's intention, an allusion becomes a decorative device. Allusion is an economical device, a figure of speech that uses a short space to draw upon the ready stock of ideas, cultural memes or emotion associated with a topic. Thus, an allusion is understandable only to those with prior knowledge of the covert reference in question, a mark of their cultural literacy; the origin of allusion is in the Latin verb ludere, lusus est "to play with, jest."
Recognizing the point of allusion's condensed riddle reinforces cultural solidarity between the maker of the allusion and the hearer: their shared familiarity with allusion bonds them. Ted Cohen finds such a "cultivation of intimacy" to be an essential element of many jokes; some aspect of the referent must be identified for the tacit association to be made. Addressing such issues is an aspect of hermeneutics. William Irwin remarks that allusion moves in only one direction: "If A alludes to B B does not allude to A; the Bible does not allude to Shakespeare, though Shakespeare may allude to the Bible." Irwin appends a note: "Only a divine author, outside of time, would seem capable of alluding to a text." This is the basis for Christian readings of Old Testament prophecy, which asserts that passages are to be read as allusions to future events due to Jesus's revelation in Luke 24:25-27. Allusion differs from the similar term intertextuality in that it is an intentional effort on the author's part.
The success of an allusion depends in part on at least some of its audience "getting" it. Allusions may be made obscure, until at last they are understood by the author alone, who thereby retreats into a private language. In discussing the richly allusive poetry of Virgil's Georgics, R. F. Thomas distinguished six categories of allusive reference, which are applicable to a wider cultural sphere; these types are: Casual Reference, "the use of language which recalls a specific antecedent, but only in a general sense", unimportant to the new context. A type of literature has grown round explorations of the allusions in such works as Alexander Pope's The Rape of the Lock or T. S. Eliot's The Waste Land. In Homer, brief allusions could be made to mythic themes of generations previous to the main narrative because they were familiar to the epic's hearers: one example is the theme of the Calydonian boarhunt. In Hellenistic Alexandria, literary culture and a fixed literary canon known to readers and hearers made a densely allusive poetry effective.
Martin Luther King, Jr. alluded to the Gettysburg Address in starting his "I Have a Dream" speech by saying'Five score years ago...". King's allusion called up parallels in two historic moments without overwhelming his speech with details. A sobriquet is an allusion. By metonymy one aspect of a p
DOS is a family of disk operating systems, hence the name. DOS consists of MS-DOS and a rebranded version under the name IBM PC DOS, both of which were introduced in 1981. Other compatible systems from other manufacturers include DR-DOS, ROM-DOS, PTS-DOS, FreeDOS. MS-DOS dominated the x86-based IBM PC compatible market between 1981 and 1995. Dozens of other operating systems use the acronym "DOS", including the mainframe DOS/360 from 1966. Others are Apple DOS, Apple ProDOS, Atari DOS, Commodore DOS, TRSDOS, AmigaDOS. Fictional operating systems have used this acronym as well, such as GLaDOS from the video game Portal. IBM PC DOS and its predecessor, 86-DOS, resembled Digital Research's CP/M—the dominant disk operating system for 8-bit Intel 8080 and Zilog Z80 microcomputers—but instead ran on Intel 8086 16-bit processors; when IBM introduced the IBM PC, built with the Intel 8088 microprocessor, they needed an operating system. Seeking an 8088-compatible build of CP/M, IBM approached Microsoft CEO Bill Gates.
IBM was sent to Digital Research, a meeting was set up. However, the initial negotiations for the use of CP/M broke down. Digital Research founder Gary Kildall refused, IBM withdrew. IBM again approached Bill Gates. Gates in turn approached Seattle Computer Products. There, programmer Tim Paterson had developed a variant of CP/M-80, intended as an internal product for testing SCP's new 16-bit Intel 8086 CPU card for the S-100 bus; the system was named QDOS, before being made commercially available as 86-DOS. Microsoft purchased 86-DOS for $50,000; this became Microsoft Disk Operating System, MS-DOS, introduced in 1981. Within a year Microsoft licensed MS-DOS to over 70 other companies, which supplied the operating system for their own hardware, sometimes under their own names. Microsoft required the use of the MS-DOS name, with the exception of the IBM variant. IBM continued to develop their version, PC DOS, for the IBM PC. Digital Research became aware that an operating system similar to CP/M was being sold by IBM, threatened legal action.
IBM responded by offering an agreement: they would give PC consumers a choice of PC DOS or CP/M-86, Kildall's 8086 version. Side-by-side, CP/M cost $200 more than PC DOS, sales were low. CP/M faded, with MS-DOS and PC DOS becoming the marketed operating system for PCs and PC compatibles. Microsoft sold MS-DOS only to original equipment manufacturers. One major reason for this was. DOS was structured such that there was a separation between the system specific device driver code and the DOS kernel. Microsoft provided an OEM Adaptation Kit which allowed OEMs to customize the device driver code to their particular system. By the early 1990s, most PCs adhered to IBM PC standards so Microsoft began selling MS-DOS in retail with MS-DOS 5.0. In the mid-1980s Microsoft developed a multitasking version of DOS; this version of DOS is referred to as "European MS-DOS 4" because it was developed for ICL and licensed to several European companies. This version of DOS supports preemptive multitasking, shared memory, device helper services and New Executable format executables.
None of these features were used in versions of DOS, but they were used to form the basis of the OS/2 1.0 kernel. This version of DOS is distinct from the released PC DOS 4.0, developed by IBM and based upon DOS 3.3. Digital Research attempted to regain the market lost from CP/M-86 with Concurrent DOS, FlexOS and DOS Plus with Multiuser DOS and DR DOS. Digital Research was bought by Novell, DR DOS became Novell DOS 7. Gordon Letwin wrote in 1995 that "DOS was, when we first wrote it, a one-time throw-away product intended to keep IBM happy so that they'd buy our languages". Microsoft expected; the company planned to over time improve MS-DOS so it would be indistinguishable from single-user Xenix, or XEDOS, which would run on the Motorola 68000, Zilog Z-8000, LSI-11. IBM, did not want to replace DOS. After AT&T began selling Unix, Microsoft and IBM began developing OS/2 as an alternative; the two companies had a series of disagreements over two successor operating systems to DOS, OS/2 and Windows.
They split development of their DOS systems as a result. The last retail version of MS-DOS was MS-DOS 6.22. The last retail version of PC DOS was PC DOS 2000, though IBM did develop PC DOS 7.10 for OEMs and internal use. The FreeDOS project began on 26 June 1994, when Microsoft announced it would no longer sell or support MS-DOS. Jim Hall posted a manifesto proposing the development of an open-source replacement. Within a few weeks, other programmers including Pat Villani and Tim Norman joined the project. A kernel, the COMMAND. COM command line interpreter, core utilities were created by pooling code they had wri
NetBSD is a free and open-source Unix-like operating system based on the Berkeley Software Distribution. It was the first open-source BSD descendant released after 386BSD was forked, it continues to be developed and is available for many platforms, including servers, handheld devices, embedded systems. The NetBSD project focuses on code clarity, careful design, portability across many computer architectures, its source code is permissively licensed. NetBSD was derived from the 4.3BSD-Reno release of the Berkeley Software Distribution from the Computer Systems Research Group of the University of California, via their Net/2 source code release and the 386BSD project. The NetBSD project began as a result of frustration within the 386BSD developer community with the pace and direction of the operating system's development; the four founders of the NetBSD project, Chris Demetriou, Theo de Raadt, Adam Glass, Charles Hannum, felt that a more open development model would benefit the project: one centered on portable, correct code.
They aimed to produce a multi-platform, production-quality, BSD-based operating system. The name "NetBSD" was suggested by De Raadt, based on the importance and growth of networks such as the Internet at that time, the distributed, collaborative nature of its development; the NetBSD source code repository was established on 21 March 1993 and the first official release, NetBSD 0.8, was made on 19 April 1993. This was derived from 386BSD 0.1 plus the version 0.2.2 unofficial patchkit, with several programs from the Net/2 release missing from 386BSD re-integrated, various other improvements. The first multi-platform release, NetBSD 1.0, was made in October 1994, being updated with 4.4BSD-Lite sources, it was free of all encumbered 4.3BSD Net/2 code. In 1994, for disputed reasons, one of the founders, Theo de Raadt, was removed from the project, he founded a new project, OpenBSD, from a forked version of NetBSD 1.0 near the end of 1995. In 1998, NetBSD 1.3 introduced the pkgsrc packages collection.
Until 2004, NetBSD 1.x releases were made at annual intervals, with minor "patch" releases in between. From release 2.0 onwards, NetBSD uses semantic versioning, each major NetBSD release corresponds to an incremented major version number, i.e. the major releases following 2.0 are 3.0, 4.0 and so on. The previous minor releases are now divided into two categories: x.y "stable" maintenance releases and x.y.z releases containing only security and critical fixes. As the project's motto suggests, NetBSD has been ported to a large number of 32- and 64-bit architectures; these range from VAX minicomputers to Pocket PC PDAs. As of 2009, NetBSD supports 57 hardware platforms; the kernel and userland for these platforms are all built from a central unified source-code tree managed by CVS. Unlike other kernels such as μClinux, the NetBSD kernel requires the presence of an MMU in any given target architecture. NetBSD's portability is aided by the use of hardware abstraction layer interfaces for low-level hardware access such as bus input/output or DMA.
Using this portability layer, device drivers can be split into "machine-independent" and "machine-dependent" components. This makes a single driver usable on several platforms by hiding hardware access details, reduces the work to port it to a new system; this permits a particular device driver for a PCI card to work without modifications, whether it is in a PCI slot on an IA-32, PowerPC, SPARC, or other architecture with a PCI bus. A single driver for a specific device can operate via several different buses, like ISA, PCI, or PC Card. In comparison, Linux device driver code must be reworked for each new architecture; as a consequence, in porting efforts by NetBSD and Linux developers, NetBSD has taken much less time to port to new hardware. This platform independence aids the development of embedded systems since NetBSD 1.6, when the entire toolchain of compilers, assemblers and other tools support cross-compiling. In 2005, as a demonstration of NetBSD's portability and suitability for embedded applications, Technologic Systems, a vendor of embedded systems hardware and demonstrated a NetBSD-powered kitchen toaster.
Commercial ports to embedded platforms, including the AMD Geode LX800, Freescale PowerQUICC processors, Marvell Orion, AMCC 405 family of PowerPC processors, Intel XScale IOP and IXP series, were available from and supported by Wasabi Systems. The NetBSD cross-compiling framework lets a developer build a complete NetBSD system for an architecture from a more powerful system of different architecture, including on a different operating system. Several embedded systems using NetBSD have required no additional software development other than toolchain and target rehost. NetBSD features pkgsrc, a framework for building and managing third-party application software packages; the pkgsrc collection consists of more than 18,000 packages as of April 2018. Building and installing packages such as KDE, GNOME, the Apache HTTP Server or Perl is performed through the use of a system of makefiles; this can automatically fetch the source code, patch, configure and install the package such that it can be removed again later.
An alternative to compiling from source is to use a precompiled binary package. In either case, any prerequisites/dependencies will be installed automatically by the package system, without need for manual intervention. Pkgsrc supports not only NetBSD, but several other BSD variants like