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131-506: The Linux kernel is a free and open source , UNIX-like kernel that is used in many computer systems worldwide. The kernel was created by Linus Torvalds in 1991 and was soon adopted as the kernel for the GNU operating system (OS) which was created to be a free replacement for Unix . Since the late 1990s, it has been included in many operating system distributions , many of which are called Linux . One such Linux kernel operating system
262-706: A Balkanisation of the "Open Source Universe". Linus Torvalds, who decided not to adopt the GPLv3 for the Linux kernel, reiterated his criticism several years later. GPLv3 improved compatibility with several free software licenses such as the Apache License, version 2.0, and the GNU Affero General Public License, which GPLv2 could not be combined with. However, GPLv3 software could only be combined and share code with GPLv2 software if
393-622: A patent infringement claim or other litigation to impair users' freedom under the license. By 1990, it was becoming apparent that a less restrictive license would be strategically useful for the C library and for software libraries that essentially did the job of existing proprietary ones; when version 2 of the GPL (GPLv2) was released in June 1991, therefore, a second license – the GNU Library General Public License –
524-526: A task switcher in Intel 80386 assembly language and a terminal driver . On 25 August 1991, Torvalds posted the following to comp.os.minix , a newsgroup on Usenet : I'm doing a (free) operating system (just a hobby, won't be big and professional like gnu) for 386(486) AT clones. This has been brewing since April, and is starting to get ready. I'd like any feedback on things people like/dislike in minix, as my OS resembles it somewhat (same physical layout of
655-403: A version control system thus far, in 2002, Linux developers adopted BitKeeper , which was made freely available to them even though it was not free software . In 2005, because of efforts to reverse-engineer it, the company which owned the software revoked its support of the Linux community. In response, Torvalds and others wrote Git . The new system was written within weeks, and in two months
786-452: A "user" and a "consumer product". It also explicitly removed the section on "Geographical Limitations", the probable removal of this section having been announced at the launch of the public consultation. The fourth discussion draft, which was the last, was released on 31 May 2007. It introduced Apache License version 2.0 compatibility (prior versions are incompatible), clarified the role of outside contractors, and made an exception to avoid
917-578: A Linux Kernel Code of Conflict was introduced on 8 March 2015. It was replaced on 16 September 2018 by a new Code of Conduct based on the Contributor Covenant . This coincided with a public apology by Torvalds and a brief break from kernel development. On 30 November 2018, complying with the Code of Conduct , Jarkko Sakkinen of Intel sent out patches replacing instances of "fuck" appearing in source code comments with suitable versions focused on
1048-408: A US federal court ruled that an open-source license is an enforceable contract. In October 2021 SFC sued Vizio over breach of contract as an end user to request source code for Vizio's TVs, a federal judge has ruled in the interim that the GPL is an enforceable contract by end users as well as a license for copyright holders. The text of the GPL is itself copyrighted , and the copyright is held by
1179-440: A bit in that more features were made available throughout the series, including support for Bluetooth , Logical Volume Manager (LVM) version 1, RAID support, InterMezzo and ext3 file systems. Version 2.6.0 was released on 17 December 2003. The development for 2.6. x changed further towards including new features throughout the series. Among the changes that have been made in the 2.6 series are: integration of μClinux into
1310-443: A licensee has no right to redistribute it, not even in modified form (barring fair use ), except under the terms of the license. One is only required to adhere to the terms of the GPL if one wishes to exercise rights normally restricted by copyright law, such as redistribution. Conversely, if one distributes copies of the work without abiding by the terms of the GPL (for instance, by keeping the source code secret), they can be sued by
1441-460: A modified derivative of a GPL licensed content management system is not required to distribute its changes to the underlying software, because the modified web portal is not being redistributed but rather hosted, and also because the web portal output is also not a derivative work of the GPL licensed content management system. There has been debate on whether it is a violation of the GPLv1 to release
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#17327756626231572-606: A niche role outside of the mainstream of private software development. However the success of FOSS Operating Systems such as Linux, BSD and the companies based on FOSS such as Red Hat , has changed the software industry's attitude and there has been a dramatic shift in the corporate philosophy concerning its development. Users of FOSS benefit from the Four Essential Freedoms to make unrestricted use of, and to study, copy, modify, and redistribute such software with or without modification. If they would like to change
1703-646: A pull request for the patches will be sent to Torvalds within a few days. Otherwise, a pull request will be sent to Torvalds during the next merge window. The merge window usually lasts two weeks and starts immediately after the release of the previous kernel version. The Git kernel source tree names all developers who have contributed to the Linux kernel in the Credits directory and all subsystem maintainers are listed in Maintainers . As with many large open-source software projects, developers are required to adhere to
1834-483: A roadmap, there are technical guidelines. Instead of a central resource allocation, there are persons and companies who all have a stake in the further development of the Linux kernel, quite independently from one another: People like Linus Torvalds and I don’t plan the kernel evolution. We don’t sit there and think up the roadmap for the next two years, then assign resources to the various new features. That's because we don’t have any resources. The resources are all owned by
1965-581: A single unified term that could refer to both concepts, although Richard Stallman argues that it fails to be neutral unlike the similar term; "Free/Libre and Open Source Software" (FLOSS). Richard Stallman 's Free Software Definition , adopted by the FSF, defines free software as a matter of liberty, not price, and that which upholds the Four Essential Freedoms. The earliest known publication of this definition of his free software definition
2096-513: A study issued by the Linux Foundation, covering the commits for the releases 4.8 to 4.13, about 1500 developers were contributing from about 200–250 companies on average. The top 30 developers contributed a little more than 16% of the code. For companies, the top contributors are Intel (13.1%) and Red Hat (7.2%), Linaro (5.6%), IBM (4.1%), the second and fifth places are held by the 'none' (8.2%) and 'unknown' (4.1%) categories. Instead of
2227-404: A variety of FOSS projects, including both free software and open-source. GNU General Public License The GNU General Public Licenses ( GNU GPL or simply GPL ) are a series of widely used free software licenses , or copyleft licenses, that guarantee end users the freedoms to run, study, share, and modify the software. The GPL was the first copyleft license for general use. It
2358-458: Is Android which is used in many mobile and embedded devices. Most of the kernel code is written in C as supported by the GNU compiler collection (GCC) which has extensions beyond standard C. The code also contains assembly code for architecture-specific logic such as optimizing memory use and task execution. The kernel has a modular design such that modules can be integrated as software components – including dynamically loaded. The kernel
2489-559: Is monolithic in an architectural sense since the entire OS runs in kernel space . Linux is provided under the GNU General Public License version 2 , although it contains files under other compatible licenses . In April 1991, Linus Torvalds, a 21-year-old computer science student at the University of Helsinki started working on an operating system, inspired by UNIX, for a personal computer. He started with
2620-490: Is a monolithic kernel rather than a microkernel was the topic of a debate between Andrew S. Tanenbaum , the creator of MINIX, and Torvalds. The Tanenbaum–Torvalds debate started in 1992 on the Usenet group comp.os.minix as a general discussion about kernel architectures. Version 0.95 was the first capable of running the X Window System . In March 1994, Linux 1.0.0 was released with 176,250 lines of code. As indicated by
2751-418: Is allowed to charge a fee for this service or do this free of charge. This latter point distinguishes the GPL from software licenses that prohibit commercial redistribution. The FSF argues that free software should not place restrictions on commercial use, and the GPL explicitly states that GPL works may be sold at any price. The GPL additionally states that a distributor may not impose "further restrictions on
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#17327756626232882-449: Is applied to ensure that end users retain the freedoms defined above. However, software running as an application program under a GPL-licensed operating system such as Linux is not required to be licensed under GPL or to be distributed with source-code availability—the licensing depends only on the used libraries and software components and not on the underlying platform. For example, if a program consists only of original source code , or
3013-427: Is combined with source code from other software components , then the custom software components need not be licensed under GPL and need not make their source code available; even if the underlying operating system used is licensed under the GPL, applications running on it are not considered derivative works. Only if GPL licensed parts are used in a program (and the program is distributed), then all other source code of
3144-577: Is drivers. Contributions are submitted as patches, in the form of text messages on the Linux kernel mailing list (LKML) (and often also on other mailing lists dedicated to particular subsystems). The patches must conform to a set of rules and to a formal language that, among other things, describes which lines of code are to be deleted and what others are to be added to the specified files. These patches can be automatically processed so that system administrators can apply them in order to make just some changes to
3275-452: Is how the compiled code was available and there are "clear directions" on where to find the source code. The FSF does not hold the copyright for a work released under the GPL unless an author explicitly assigns copyrights to the FSF (which seldom happens except for programs that are part of the GNU project). Only the individual copyright holders have the authority to sue when a license violation
3406-431: Is licensed under GPLv2 only. The "or any later version" clause is sometimes known as a "lifeboat clause" since it allows combinations between different versions of GPL-licensed software to maintain compatibility. The original GPL was written by Richard Stallman in 1989, for use with programs released as part of the GNU project. It was based on a unification of similar licenses used for early versions of GNU Emacs (1985),
3537-496: Is maintained by a single maintainer, these patches are sent as e-mails to the maintainer of the subsystem with the appropriate mailing list in Cc. The maintainer and the readers of the mailing list will review the patches and provide feedback. Once the review process has finished the subsystem maintainer accepts the patches in the relevant Git kernel tree. If the changes to the Linux kernel are bug fixes that are considered important enough,
3668-500: Is prohibited by copyright law . The FSF argues that freedom-respecting free software should also not restrict commercial use and distribution (including redistribution): In purely private (or internal) use—with no sales and no distribution—the software code may be modified and parts reused without requiring the source code to be released. For sales or distribution, the entire source code needs to be made available to end users, including any code changes and additions—in that case, copyleft
3799-549: Is significantly responsible for rising use of Linux overall. The cost to redevelop version 2.6.0 of the Linux kernel in a traditional proprietary development setting has been estimated to be US$ 612 million (€467M, £394M) in 2004 prices using the COCOMO person-month estimation model. In 2006, a study funded by the European Union put the redevelopment cost of kernel version 2.6.8 higher, at €882M ($ 1.14bn, £744M). This topic
3930-499: Is suspected. Software under the GPL may be run for all purposes, including commercial purposes and even as a tool for creating proprietary software , such as when using GPL-licensed compilers . Users or companies who distribute GPL-licensed works (e.g. software), may charge a fee for copies or give them free of charge. This distinguishes the GPL from shareware software licenses that allow copying for personal use but prohibit commercial distribution or proprietary licenses where copying
4061-534: Is today better known as Mozilla Firefox and Thunderbird . Netscape's act prompted Raymond and others to look into how to bring the FSF's Free software ideas and perceived benefits to the commercial software industry. They concluded that FSF's social activism was not appealing to companies like Netscape, and looked for a way to rebrand the Free software movement to emphasize the business potential of sharing and collaborating on software source code. The new name they chose
Linux kernel - Misplaced Pages Continue
4192-663: Is used by the Open Source Initiative (OSI) to determine whether a software license qualifies for the organization's insignia for open-source software . The definition was based on the Debian Free Software Guidelines , written and adapted primarily by Bruce Perens . Perens did not base his writing on the Four Essential Freedoms of free software from the Free Software Foundation , which were only later available on
4323-698: The ASP loophole in the GPL . As there were concerns expressed about the administrative costs of checking code for this additional requirement, it was decided to keep the GPL and the AGPL license separated. Others, notably some high-profile Linux kernel developers such as Linus Torvalds , Greg Kroah-Hartman , and Andrew Morton , commented to the mass media and made public statements about their objections to parts of discussion drafts 1 and 2. The kernel developers referred to GPLv3 draft clauses regarding DRM / Tivoization , patents, and "additional restrictions", and warned of
4454-508: The AGPL (v1) , and patent deals between Microsoft and distributors of free and open-source software, which some viewed as an attempt to use patents as a weapon against the free software community. Version 3 was developed as an attempt to address these concerns and was officially released on 29 June 2007. Version 1 of the GNU GPL, released on 25 February 1989, was written to protect against
4585-479: The Contributor Covenant , a code of conduct intended to address harassment of minority contributors. Additionally, to prevent offense the use of inclusive terminology within the source code is mandated. Free and open-source software Free and open-source software ( FOSS ) is software that is available under a license that grants the right to use, modify, and distribute the software, modified or not, to everyone free of charge. The public availability of
4716-477: The GNU Debugger , and the GNU C Compiler . These licenses contained similar provisions to the modern GPL, but were specific to each program, rendering them incompatible, despite being the same license. Stallman's goal was to produce one license that could be used for any project, thus making it possible for many projects to share code. The second version of the license, version 2, was released in 1991. Over
4847-614: The Lesser General Public License and even further distinct from the more widely-used permissive software licenses such as BSD , MIT , and Apache . Historically, the GPL license family has been one of the most popular software licenses in the free and open-source software (FOSS) domain. Prominent free software programs licensed under the GPL include the Linux kernel and the GNU Compiler Collection (GCC). David A. Wheeler argues that
4978-603: The Native POSIX Thread Library (NPTL), User-mode Linux integration into the mainline kernel sources, SELinux integration into the mainline kernel sources, InfiniBand support, and considerably more. Starting with 2.6.x releases, the kernel supported a large number of file systems; some designed for Linux, like ext3 , ext4 , FUSE , Btrfs , and others native to other operating systems like JFS , XFS , Minix, Xenix , Irix , Solaris , System V , Windows and MS-DOS . Though development had not used
5109-492: The Software Freedom Law Center . According to Stallman, the most important changes were in relation to software patents , free software license compatibility, the definition of "source code", and hardware restrictions on software modifications, such as tivoization . Other changes related to internationalization, how license violations are handled, and how additional permissions could be granted by
5240-738: The United Space Alliance , which manages the computer systems for the International Space Station (ISS), regarding why they chose to switch from Windows to Linux on the ISS. In 2017, the European Commission stated that "EU institutions should become open source software users themselves, even more than they already are" and listed open source software as one of the nine key drivers of innovation, together with big data , mobility, cloud computing and
5371-555: The WIPO Copyright Treaty , and that those who convey the work waive all legal power to prohibit circumvention of the technical protection measure "to the extent such circumvention is effected by exercising rights under this License with respect to the covered work". This means that users cannot be held liable for circumventing DRM implemented using GPLv3-licensed code under laws such as the U.S. Digital Millennium Copyright Act (DMCA). The distribution rights granted by
Linux kernel - Misplaced Pages Continue
5502-1058: The atomic CMPXCHG instruction introduced with the i486 to allow reliable mutexes —making the 3.7 kernel series the last one still supporting the original processor. The same series unified support for the ARM processor. The numbering change from 2.6.39 to 3.0, and from 3.19 to 4.0, involved no meaningful technical differentiation; the major version number was increased simply to avoid large minor numbers. Stable 3.x.y kernels were released until 3.19 in February 2015. Version 3.11, released on 2 September 2013, added many new features such as new O_TMPFILE flag for open(2) to reduce temporary file vulnerabilities, experimental AMD Radeon dynamic power management, low-latency network polling, and zswap (compressed swap cache). In April 2015, Torvalds released kernel version 4.0. By February 2015, Linux had received contributions from nearly 12,000 programmers from more than 1,200 companies, including some of
5633-617: The hacker community at the MIT Artificial Intelligence Laboratory , announced the GNU project , saying that he had become frustrated with the effects of the change in culture of the computer industry and its users. Software development for the GNU operating system began in January 1984, and the Free Software Foundation (FSF) was founded in October 1985. An article outlining the project and its goals
5764-494: The internet of things . In 2020, the European Commission adopted its Open Source Strategy 2020-2023 , including encouraging sharing and reuse of software and publishing Commission's source code as key objectives. Among concrete actions there is also to set up an Open Source Programme Office in 2020 and in 2022 it launched its own FOSS repository https://code.europa.eu/ . In 2021, the Commission Decision on
5895-609: The open-source software movement are online social movements behind widespread production, adoption and promotion of FOSS, with the former preferring to use the terms FLOSS , free or libre. "Free and open-source software" (FOSS) is an umbrella term for software that is simultaneously considered both free software and open-source software . The precise definition of the terms "free software" and "open-source software" applies them to any software distributed under terms that allow users to use, modify, and redistribute said software in any manner they see fit, without requiring that they pay
6026-573: The "ftp.funet.fi" – FTP server of the Finnish University and Research Network ( FUNET ). It was not even executable since its code still needed Minix to compile and test it. On 5 October 1991, Torvalds announced the first "official" version of Linux, version 0.02. [As] I mentioned a month ago, I'm working on a free version of a Minix-lookalike for AT-386 computers. It has finally reached the stage where it's even usable (though may not be depending on what you want), and I am willing to put out
6157-759: The AMD Radeon FreeSync and NVIDIA Xavier display, fixes for F2FS , EXT4 and XFS , restored support for swap files on the Btrfs file system and continued work on the Intel Icelake Gen11 graphics and on the NXP i.MX8 SoCs. This release was noticeably larger than the rest, Torvalds mentioning that "The overall changes for all of the 5.0 release are much bigger." A total of 1,991 developers, of whom 334 were first-time collaborators, added more than 553,000 lines of code to version 5.8, breaking
6288-638: The EU. These recommendations are to be taken into account later in the same year in Commission's proposal of the "Interoperable Europe Act" . While copyright is the primary legal mechanism that FOSS authors use to ensure license compliance for their software, other mechanisms such as legislation, patents, and trademarks have implications as well. In response to legal issues with patents and the Digital Millennium Copyright Act (DMCA),
6419-417: The European Union. As of 7 March 2011, using then-current LOC (lines of code) of a 2.6.x Linux kernel and wage numbers with David A. Wheeler's calculations it would cost approximately $ 3bn (about €2.2bn) to redevelop the Linux kernel as it keeps getting bigger. An updated calculation as of 26 September 2018, using then-current 20,088,609 LOC (lines of code) for the 4.14.14 Linux kernel and
6550-603: The FOSS ecosystem, several projects decided against upgrading to GPLv3. For instance the Linux kernel , the BusyBox project, AdvFS , Blender , and the VLC media player decided against adopting the GPLv3. Apple , a user of GCC and a heavy user of both DRM and patents, switched the compiler in its Xcode IDE from GCC to Clang , which is another FOSS compiler but is under a permissive license . LWN speculated that Apple
6681-604: The Free Software Foundation released version 3 of its GNU General Public License (GNU GPLv3) in 2007 that explicitly addressed the DMCA and patent rights. After the development of the GNU GPLv3 in 2007, the FSF (as the copyright holder of many pieces of the GNU system) updated many of the GNU programs' licenses from GPLv2 to GPLv3. On the other hand, the adoption of the new GPL version was heavily discussed in
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#17327756626236812-580: The Free Software Foundation. The FSF permits people to create new licenses based on the GPL, as long as the derived licenses do not use the GPL preamble without permission. This is discouraged, however, since such a license might be incompatible with the GPL and causes a perceived license proliferation . Other licenses created by the GNU project include the GNU Lesser General Public License , GNU Free Documentation License , and GNU Affero General Public License . The text of
6943-404: The GPL for modified versions of the work are not unconditional. When someone distributes a GPL licensed work plus their own modifications, the requirements for distributing the whole work cannot be any greater than the requirements that are in the GPL. This requirement is known as copyleft. It earns its legal power from the use of copyright on software programs. Because a GPL work is copyrighted,
7074-527: The GPL is not itself under the GPL. The license's copyright disallows modification of the license. Copying and distributing the license is allowed since the GPL requires recipients to get "a copy of this License along with the Program". According to the GPL FAQ, anyone can make a new license using a modified version of the GPL as long as they use a different name for the license, do not mention "GNU", and remove
7205-431: The GPL licensed program, they may still use the software within their organization however they like, and works (including programs) constructed by the use of the program are not required to be covered by this license. Software developer Allison Randal argued that the GPLv3 as a license is unnecessarily confusing for lay readers, and could be simplified while retaining the same conditions and legal force. In April 2017,
7336-523: The GPLv2 license used had the optional "or later" clause and the software was upgraded to GPLv3. While the "GPLv2 or any later version" clause is considered by FSF as the most common form of licensing GPLv2 software, Toybox developer Rob Landley described it as a lifeboat clause . Software projects licensed with the optional "or later" clause include the GNU Project , while a prominent example without
7467-546: The Linux 2.2.13 code for the support of the S/390 architecture. Version 2.4.0, released on 4 January 2001, contained support for ISA Plug and Play , USB , and PC Cards . Linux 2.4 added support for the Pentium 4 and Itanium (the latter introduced the ia64 ISA that was jointly developed by Intel and Hewlett-Packard to supersede the older PA-RISC ), and for the newer 64-bit MIPS processor. Development for 2.4. x changed
7598-669: The Linux kernel for its OS. Torvalds labeled the kernel with major version 0 to indicate that it was not yet intended for general use. Version 0.11, released in December 1991, was the first version to be self-hosted ; compiled on a computer running the Linux kernel. When Torvalds released version 0.12 in February 1992, he adopted the GNU General Public License version 2 (GPLv2) over his previous self-drafted license, which had not permitted commercial redistribution. In contrast to Unix , all source files of Linux are freely available, including device drivers . The initial success of Linux
7729-540: The Software Package Data Exchange (SPDX). The license includes instructions to specify "version 2 of the License, or (at your option) any later version" to allow the flexible optional use of either version 2 or 3, but some developers change this to specify "version 2" only. In late 2005, the Free Software Foundation (FSF) announced work on version 3 of the GPL (GPLv3). On 16 January 2006,
7860-402: The actual causes of the many issues with Linux on notebooks such as the unnecessary power consumption. Mergers have affected major open-source software. Sun Microsystems (Sun) acquired MySQL AB , owner of the popular open-source MySQL database, in 2008. Oracle in turn purchased Sun in January 2010, acquiring their copyrights, patents, and trademarks. Thus, Oracle became the owner of both
7991-470: The author(s) of the software a royalty or fee for engaging in the listed activities. Although there is an almost complete overlap between free-software licenses and open-source-software licenses, there is a strong philosophical disagreement between the advocates of these two positions. The terminology of FOSS was created to be a neutral on these philosophical disagreements between the Free Software Foundation (FSF) and Open Source Initiative (OSI) and have
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#17327756626238122-429: The clause is the Linux kernel. The final version of the license text was published on 29 June 2007. The terms and conditions of the GPL must be made available to anybody receiving a copy of a work that has a GPL applied to it ("the licensee"). Any licensee who adheres to the terms and conditions is given permission to modify the work, as well as to copy and redistribute the work or any derivative version. The licensee
8253-417: The code or to incrementally upgrade to the next version. Linux is distributed also in GNU zip (gzip) and bzip2 formats. A developer who wants to change the Linux kernel writes and tests a code change. Depending on how significant the change is and how many subsystems it modifies, the change will either be submitted as a single patch or in multiple patches of source code . In case of a single subsystem that
8384-434: The concept of freely distributed software and universal access to an application's source code . A Microsoft executive publicly stated in 2001 that "Open-source is an intellectual property destroyer. I can't imagine something that could be worse than this for the software business and the intellectual-property business." Companies have indeed faced copyright infringement issues when embracing FOSS. For many years FOSS played
8515-427: The copyleft provided by the GPL was crucial to the success of Linux -based systems, giving the programmers who contributed to the kernel assurance that their work would benefit the whole world and remain free, rather than being exploited by software companies that would not have to give anything back to the community. In 2007, the third version of the license (GPLv3) was released to address some perceived problems with
8646-470: The copyright holder. The concept of "software propagation", as a term for the copying and duplication of software, was explicitly defined. The public consultation process was coordinated by the Free Software Foundation with assistance from Software Freedom Law Center, Free Software Foundation Europe , and other free software groups. Comments were collected from the public via the gplv3.fsf.org web portal, using purpose-written software called stet . During
8777-502: The copyright law was extended to computer programs in the United States —previously, computer programs could be considered ideas, procedures, methods, systems, and processes, which are not copyrightable. Early on, closed-source software was uncommon until the mid-1970s to the 1980s, when IBM implemented in 1983 an "object code only" policy, no longer distributing source code. In 1983, Richard Stallman , longtime member of
8908-412: The current US national average programmer salary of $ 75,506 show that it would cost approximately $ 14,725,449,000 (£11,191,341,000) to rewrite the existing code. Most who use Linux do so via a Linux distribution . Some distributions ship the vanilla or stable kernel. However, several vendors (such as Red Hat and Debian ) maintain a customized source tree. These are usually updated at a slower pace than
9039-530: The file-system (due to practical reasons) among other things). I've currently ported bash (1.08) and gcc (1.40), and things seem to work. This implies that I'll get something practical within a few months [...] Yes - it's free of any minix code, and it has a multi-threaded fs. It is NOT protable [ sic ] (uses 386 task switching etc), and it probably never will support anything other than AT-harddisks, as that's all I have :-(. On 17 September 1991, Torvalds prepared version 0.01 of Linux and put on
9170-399: The first "discussion draft" of GPLv3 was published, and the public consultation began. The public consultation was originally planned for nine to fifteen months, but ultimately lasted eighteen months, with four drafts being published. The official GPLv3 was released by the FSF on 29 June 2007. GPLv3 was written by Richard Stallman, with legal counsel from Eben Moglen and Richard Fontana from
9301-412: The first official kernel made using it was released. In 2005 the stable team was formed as a response to the lack of a kernel tree where people could work on bug fixes , and it would keep updating stable versions. In February 2008 the linux-next tree was created to serve as a place where patches aimed to be merged during the next development cycle gathered. Several subsystem maintainers also adopted
9432-399: The following 15 years, members of the free software community became concerned over problems in the GPLv2 license that could let someone exploit GPL-licensed software in ways contrary to the license's intent. These problems included tivoization (the inclusion of GPL-licensed software in hardware that refuses to run modified versions of its software), compatibility issues similar to those of
9563-562: The functionality of software they can bring about changes to the code and, if they wish, distribute such modified versions of the software or often − depending on the software's decision making model and its other users − even push or request such changes to be made via updates to the original software. Manufacturers of proprietary, closed-source software are sometimes pressured to building in backdoors or other covert, undesired features into their software. Instead of having to trust software vendors, users of FOSS can inspect and verify
9694-416: The goal of developing the most efficient software for its users or use-cases while proprietary software is typically meant to generate profits . Furthermore, in many cases more organizations and individuals contribute to such projects than to proprietary software. It has been shown that technical superiority is typically the primary reason why companies choose open source software. According to Linus's law
9825-567: The government charged that bundled software was anticompetitive. While some software was still being provided without monetary cost and license restriction, there was a growing amount of software that was only at a monetary cost with restricted licensing. In the 1970s and early 1980s, some parts of the software industry began using technical measures (such as distributing only binary copies of computer programs ) to prevent computer users from being able to use reverse engineering techniques to study and customize software they had paid for. In 1980,
9956-491: The historical potential of an " economy of abundance " for the new digital world , FOSS may lay down a plan for political resistance or show the way towards a potential transformation of capitalism . According to Yochai Benkler , Jack N. and Lillian R. Berkman Professor for Entrepreneurial Legal Studies at Harvard Law School , free software is the most visible part of a new economy of commons-based peer production of information, knowledge, and culture. As examples, he cites
10087-589: The kernel community at the 2017 Embedded Linux Conference Europe. The issues brought up were discussed a few days later at the Maintainers Summit. Concerns over the lack of consistency in how maintainers responded to patches submitted by developers were echoed by Shuah Khan , the maintainer of the kernel self-test framework. Torvalds contended that there would never be consistency in the handling of patches because different kernel subsystems have, over time, adopted different development processes. Therefore, it
10218-567: The kernel so that old programs would work. Version 3.0 was released on 22 July 2011. On 30 May 2011, Torvalds announced that the big change was "NOTHING. Absolutely nothing." and asked, "...let's make sure we really make the next release not just an all new shiny number, but a good kernel too." After the expected 6–7 weeks of the development process, it would be released near the 20th anniversary of Linux. On 11 December 2012, Torvalds decided to reduce kernel complexity by removing support for i386 processors—specifically by not having to emulate
10349-403: The kernel with system software (e.g., the GNU C Library , systemd , and other Unix utilities and daemons ) and a wide selection of application software , but their usage share in desktops is low in comparison to other operating systems. Since Android , which is Linux, accounts for the majority of mobile device operating systems, and due to its rising use in embedded devices , Android
10480-536: The legal distinction between a license and a contract is an important one: contracts are enforceable by contract law , whereas licenses are enforced under copyright law . However, this distinction is not useful in the many jurisdictions where there are no differences between contracts and licenses, such as civil law systems. Those who do not accept the GPL's terms and conditions do not have permission, under copyright law, to copy or distribute GPL-licensed software or derivative works. However, if they do not redistribute
10611-485: The level of interest in a particular project. However, unlike close-sourced software, improvements can be made by anyone who has the motivation, time and skill to do so. A common obstacle in FOSS development is the lack of access to some common official standards, due to costly royalties or required non-disclosure agreements (e.g., for the DVD-Video format). There is often less certainty of FOSS projects gaining
10742-420: The license. Copyleft applies only when a person seeks to redistribute the program. Developers may make private modified versions with no obligation to divulge the modifications, as long as they do not distribute the modified software to anyone else. Copyleft applies only to the software, and not to its output (unless that output is itself a derivative work of the program). For example, a public web portal running
10873-470: The linux.conf.au (LCA) conference in 2018, developers expressed the view that the culture of the community has gotten much better in the past few years. Daniel Vetter, the maintainer of the Intel drm/i915 graphics kernel driver, commented that the "rather violent language and discussion" in the kernel community has decreased or disappeared. Laurent Pinchart asked developers for feedback on their experiences with
11004-532: The mainline kernel sources, PAE support, support for several new lines of CPUs , integration of Advanced Linux Sound Architecture (ALSA) into the mainline kernel sources, support for up to 2 users (up from 2), support for up to 2 process IDs (64-bit only, 32-bit architectures still limited to 2), substantially increased the number of device types and the number of devices of each type, improved 64-bit support, support for file systems which support file sizes of up to 16 terabytes , in-kernel preemption , support for
11135-431: The major change in GPLv2 was the "Liberty or Death" clause, as he calls it – Section 7. The section says that licensees may distribute a GPL-covered work only if they can satisfy all of the license's obligations, despite any other legal obligations they might have. In other words, the obligations of the license may not be severed due to conflicting obligations. This provision is intended to discourage any party from using
11266-545: The more people who can see and test a set of code, the more likely any flaws will be caught and fixed quickly. However, this does not guarantee a high level of participation. Having a grouping of full-time professionals behind a commercial product can in some cases be superior to FOSS. Furthermore, publicized source code might make it easier for hackers to find vulnerabilities in it and write exploits. This however assumes that such malicious hackers are more effective than white hat hackers which responsibly disclose or help fix
11397-477: The most popular proprietary database and the most popular open-source database. Oracle's attempts to commercialize the open-source MySQL database have raised concerns in the FOSS community. Partly in response to uncertainty about the future of MySQL, the FOSS community forked the project into new database systems outside of Oracle's control. These include MariaDB , Percona , and Drizzle . All of these have distinct names; they are distinct projects and cannot use
11528-640: The open source licensing and reuse of Commission software (2021/C 495 I/01) was adopted, under which, as a general principle, the European Commission may release software under EUPL or another FOSS license, if more appropriate. There are exceptions though. In May 2022, the Expert group on the Interoperability of European Public Services came published 27 recommendations to strengthen the interoperability of public administrations across
11659-453: The original author under copyright law. Copyright law has historically been used to prevent distribution of work by parties not authorized by the creator. Copyleft uses the same copyright laws to accomplish a very different goal. It grants rights to distribution to all parties insofar as they provide the same rights to subsequent ones, and they to the next, etc. In this way, the GPL and other copyleft licenses attempt to enforce libre access to
11790-544: The parties stipulated that Google would pay no damages. Oracle appealed to the Federal Circuit , and Google filed a cross-appeal on the literal copying claim. By defying ownership regulations in the construction and use of information—a key area of contemporary growth —the Free/Open Source Software (FOSS) movement counters neoliberalism and privatization in general. By realizing
11921-509: The parties who would receive the covered work from you, a discriminatory patent license ... This aimed to make such future deals ineffective. The license was also meant to cause Microsoft to extend the patent licenses it granted to Novell customers for the use of GPLv3 software to all users of that GPLv3 software; this was possible only if Microsoft was legally a "conveyor" of the GPLv3 software. Early drafts of GPLv3 also let licensors add an AGPL -like requirement that would have plugged
12052-457: The perceived problems of a Microsoft–Novell style agreement, saying in Section 11 paragraph 6 that: You may not convey a covered work if you are a party to an arrangement with a third party that is in the business of distributing software, under which you make payment to the third party based on the extent of your activity of conveying the work, and under which the third party grants, to any of
12183-409: The preamble, though the preamble can be used in a modified license if permission to use it is obtained from the Free Software Foundation (FSF). According to the FSF, "The GPL does not require you to release your modified version or any part of it. You are free to make modifications and use them privately, without ever releasing them." However, if one releases a GPL-licensed entity to the public, there
12314-526: The program needs to be made available under the same license terms. The GNU Lesser General Public License (LGPL) was created to have a weaker copyleft than the GPL, in that it does not require custom-developed source code (distinct from the LGPL licensed parts) to be made available under the same license terms. The fifth section of version 3 states that no GPL-licensed code shall be considered an effective "technical protection measure" as defined by Article 11 of
12445-420: The public consultation process, 962 comments were submitted for the first draft. By the end of the comment period, a total of 2,636 comments had been submitted. The third draft was released on 28 March 2007. This draft included language intended to prevent patent-related agreements such as the controversial Microsoft-Novell patent agreement , and restricted the anti-tivoization clauses to a legal definition of
12576-526: The record previously held by version 4.9. According to the Stack Overflow's annual Developer Survey of 2019, more than the 53% of all respondents have developed software for Linux and about 27% for Android , although only about 25% develop with Linux-based operating systems. Most websites run on Linux-based operating systems , and all of the world's 500 most powerful supercomputers use some form of OS based on Linux. Linux distributions bundle
12707-418: The required resources and participation for continued development than commercial software backed by companies. However, companies also often abolish projects for being unprofitable, yet large companies may rely on, and hence co-develop, open source software. On the other hand, if the vendor of proprietary software ceases development, there are no alternatives; whereas with FOSS, any user who needs it still has
12838-484: The right, and the source-code, to continue to develop it themself, or pay a 3rd party to do so. As the FOSS operating system distributions of Linux has a lower market share of end users there are also fewer applications available. "We migrated key functions from Windows to Linux because we needed an operating system that was stable and reliable -- one that would give us in-house control. So if we needed to patch, adjust, or adapt, we could." Official statement of
12969-426: The rights granted by the GPL". This forbids activities such as distributing the software under a non-disclosure agreement or contract. The fourth section for version 2 of the license and the seventh section of version 3 require that programs distributed as pre-compiled binaries be accompanied by a copy of the source code, a written offer to distribute the source code via the same mechanism as the pre-compiled binary, or
13100-470: The second version (GPLv2) which were discovered during the latter's long-time usage. To keep the license current, the GPL license includes an optional "any later version" clause, allowing users to choose between the original terms or the terms in new versions as updated by the FSF. Software projects licensed with the optional "or later" clause include the GNU Project, while projects like the Linux kernel
13231-440: The source code in obfuscated form, such as in cases in which the author is less willing to make the source code available. The consensus was that while unethical, it was not considered a violation. The issue was clarified when the license was altered with v2 to require that the "preferred" version of the source code be made available. The GPL was designed as a license , rather than a contract. In some common law jurisdictions,
13362-971: The source code is, therefore, a necessary but not sufficient condition. FOSS is an inclusive umbrella term for free software and open-source software . FOSS is in contrast to proprietary software , where the software is under restrictive copyright or licensing and the source code is hidden from the users. FOSS maintains the software user's civil liberty rights via the " Four Essential Freedoms " of free software. Other benefits of using FOSS include decreased software costs, increased security against malware , stability, privacy , opportunities for educational usage, and giving users more control over their own hardware. Free and open-source operating systems such as Linux distributions and descendants of BSD are widely used today, powering millions of servers , desktops , smartphones , and other devices. Free-software licenses and open-source licenses are used by many software packages today. The free software movement and
13493-521: The source code themselves and can put trust on a community of volunteers and users. As proprietary code is typically hidden from public view, only the vendors themselves and hackers may be aware of any vulnerabilities in them while FOSS involves as many people as possible for exposing bugs quickly. FOSS is often free of charge although donations are often encouraged. This also allows users to better test and compare software. FOSS allows for better collaboration among various parties and individuals with
13624-516: The sources for wider distribution. It is just version 0.02...but I've successfully run bash, gcc, gnu-make, gnu-sed, compress, etc. under it. Linux grew rapidly as many developers, including the MINIX community, contributed to the project. At the time, the GNU Project had completed many components for its free UNIX replacement, the GNU OS , but its kernel, GNU Hurd , was incomplete. The project adopted
13755-504: The suffix -next for trees containing code which they mean to submit for inclusion in the next release cycle. As of January 2014, the in-development version of Linux is held in an unstable branch named linux-next . The 20th anniversary of Linux was celebrated by Torvalds in July 2011 with the release of version 3.0.0. As 2.6 had been the version number for 8 years, a new uname26 personality that reports 3.x as 2.6.40+x had to be added to
13886-417: The terms of GPLv1 could be combined with software under more permissive terms, as this would not change the terms under which the whole could be distributed. However, software distributed under GPLv1 could not be combined with software distributed under a more restrictive license, as this would conflict with the requirement that the whole be distributable under the terms of GPLv1. According to Richard Stallman,
14017-518: The trademarked name MySQL. In August 2010, Oracle sued Google , claiming that its use of Java in Android infringed on Oracle's copyrights and patents. In May 2012, the trial judge determined that Google did not infringe on Oracle's patents and ruled that the structure of the Java APIs used by Google was not copyrightable. The jury found that Google infringed a small number of copied files, but
14148-446: The two main methods by which software distributors restricted the freedoms that define free software. The first problem was that distributors might publish only binary files that are executable, but not readable or modifiable by humans. To prevent this, GPLv1 stated that copying and distributing copies of any portion of the program must also make the human-readable source code available under the same licensing terms. The second problem
14279-407: The vanilla branch, and they usually include all fixes from the relevant stable branch, but at the same time they can also add support for drivers or features which had not been released in the vanilla version the distribution vendor started basing its branch from. The community of Linux kernel developers comprises about 5000–6000 members. According to the "2017 State of Linux Kernel Development",
14410-442: The various corporations who use and contribute to Linux, as well as by the various independent contributors out there. It's those people who own the resources who decide... Notable conflicts among Linux kernel developers: Prominent Linux kernel developers have been aware of the importance of avoiding conflicts between developers. For a long time there was no code of conduct for kernel developers due to opposition by Torvalds. However,
14541-940: The version number, it was the first version considered suitable for a production environment . In June 1996, after release 1.3, Torvalds decided that Linux had evolved enough to warrant a new major number, and so labeled the next release as version 2.0.0. Significant features of 2.0 included symmetric multiprocessing (SMP), support for more processors types and support for selecting specific hardware targets and for enabling architecture-specific features and optimizations. The make *config family of commands of kbuild enable and configure options for building ad hoc kernel executables ( vmlinux ) and loadable modules. Version 2.2, released on 20 January 1999, improved locking granularity and SMP management, added m68k , PowerPC , Sparc64 , Alpha , and other 64-bit platforms support. Furthermore, it added new file systems including Microsoft 's NTFS read-only capability. In 1999, IBM published its patches to
14672-837: The vulnerabilities, that no code leaks or exfiltrations occur and that reverse engineering of proprietary code is a hindrance of significance for malicious hackers. Sometimes, FOSS is not compatible with proprietary hardware or specific software. This is often due to manufacturers obstructing FOSS such as by not disclosing the interfaces or other specifications needed for members of the FOSS movement to write drivers for their hardware - for instance as they wish customers to run only their own proprietary software or as they might benefit from partnerships. While FOSS can be superior to proprietary equivalents in terms of software features and stability, in many cases it has more unfixed bugs and missing features when compared to similar commercial software. This varies per case, and usually depends on
14803-485: The web. Perens subsequently stated that he felt Eric Raymond 's promotion of open-source unfairly overshadowed the Free Software Foundation's efforts and reaffirmed his support for free software. In the following 2000s, he spoke about open source again. From the 1950s and on through the 1980s, it was common for computer users to have the source code for all programs they used, and the permission and ability to modify it for their own use. Software , including source code,
14934-716: The word 'hug'. Developers who feel treated unfairly can report this to the Linux Foundation Technical Advisory Board. In July 2013, the maintainer of the USB 3.0 driver Sage Sharp asked Torvalds to address the abusive commentary in the kernel development community. In 2014, Sharp backed out of Linux kernel development, saying that "The focus on technical excellence, in combination with overloaded maintainers, and people with different cultural and social norms, means that Linux kernel maintainers are often blunt, rude, or brutal to get their job done". At
15065-515: The work and all derivatives. Many distributors of GPL licensed programs bundle the source code with the executables . An alternative method of satisfying the copyleft is to provide a written offer to provide the source code on a physical medium (such as a CD) upon request. In practice, many GPL licensed programs are distributed over the Internet, and the source code is made available over FTP or HTTP . For Internet distribution, this complies with
15196-517: The world's largest software and hardware vendors. Version 4.1 of Linux, released in June 2015, contains over 19.5 million lines of code contributed by almost 14,000 programmers. Linus Torvalds announced that kernel version 4.22 would instead be numbered 5.0 in March 2019, stating that "'5.0' doesn't mean anything more than that the 4.x numbers started getting big enough that I ran out of fingers and toes." It featured many major additions such as support for
15327-510: The written offer to obtain the source code that the user got when they received the pre-compiled binary under the GPL. The second section of version 2 and the fifth section of version 3 also require giving "all recipients a copy of this License along with the Program". Version 3 of the license allows making the source code available in additional ways in fulfillment of the seventh section. These include downloading source code from an adjacent network server or by peer-to-peer transmission, provided that
15458-534: Was "Open-source", and quickly Bruce Perens , publisher Tim O'Reilly , Linus Torvalds, and others signed on to the rebranding. The Open Source Initiative was founded in February 1998 to encourage the use of the new term and evangelize open-source principles. While the Open Source Initiative sought to encourage the use of the new term and evangelize the principles it adhered to, commercial software vendors found themselves increasingly threatened by
15589-531: Was agreed upon that each kernel subsystem maintainer would document the rules for patch acceptance. Linux is evolution, not intelligent design ! The kernel source code, a.k.a. source tree, is managed in the Git version control system – also created by Torvalds. As of 2021, the 5.11 release of the Linux kernel had around 30.34 million lines of code. Roughly 14% of the code is part of the "core," including architecture-specific code, kernel code, and mm code, while 60%
15720-447: Was commonly shared by individuals who used computers, often as public-domain software (FOSS is not the same as public domain software, as public domain software does not contain copyrights ). Most companies had a business model based on hardware sales, and provided or bundled software with hardware, free of charge. By the late 1960s, the prevailing business model around software was changing. A growing and evolving software industry
15851-462: Was competing with the hardware manufacturer's bundled software products; rather than funding software development from hardware revenue, these new companies were selling software directly. Leased machines required software support while providing no revenue for software, and some customers who were able to better meet their own needs did not want the costs of software bundled with hardware product costs. In United States vs. IBM , filed January 17, 1969,
15982-490: Was driven by programmers and testers across the world. With the support of the POSIX APIs, through the libC that, whether needed, acts as an entry point to the kernel address space, Linux could run software and applications that had been developed for Unix. On 19 January 1992, the first post to the new newsgroup alt.os.linux was submitted. On 31 March 1992, the newsgroup was renamed comp.os.linux . The fact that Linux
16113-475: Was in the February 1986 edition of the FSF's now-discontinued GNU's Bulletin publication. The canonical source for the document is in the philosophy section of the GNU Project website. As of August 2017 , it is published in 40 languages. To meet the definition of "free software", the FSF requires the software's licensing respect the civil liberties / human rights of what the FSF calls the software user's " Four Essential Freedoms ". The Open Source Definition
16244-439: Was introduced at the same time and numbered with version 2 to show that both were complementary. The version numbers diverged in 1999 when version 2.1 of the LGPL was released, which renamed it the GNU Lesser General Public License to reflect its place in the philosophy. The GPLv2 was also modified to refer to the new name of the LGPL, but its version number remained the same, resulting in the original GPLv2 not being recognised by
16375-572: Was motivated partly by a desire to avoid GPLv3. The Samba project also switched to GPLv3, so Apple replaced Samba in their software suite by a closed-source, proprietary software alternative. Leemhuis criticizes the prioritization of skilled developers who − instead of fixing issues in already popular open-source applications and desktop environments − create new, mostly redundant software to gain fame and fortune. He also criticizes notebook manufacturers for optimizing their own products only privately or creating workarounds instead of helping fix
16506-492: Was originally written by Richard Stallman , the founder of the Free Software Foundation (FSF), for the GNU Project . The license grants the recipients of a computer program the rights of the Free Software Definition . The licenses in the GPL series are all copyleft licenses, which means that any derivative work must be distributed under the same or equivalent license terms. It is more restrictive than
16637-476: Was published in March 1985 titled the GNU Manifesto . The manifesto included significant explanation of the GNU philosophy, Free Software Definition and " copyleft " ideas. The FSF takes the position that the fundamental issue Free software addresses is an ethical one—to ensure software users can exercise what it calls " The Four Essential Freedoms ". The Linux kernel , created by Linus Torvalds ,
16768-578: Was released as freely modifiable source code in 1991. Initially, Linux was not released under either a Free software or an Open-source software license. However, with version 0.12 in February 1992, he relicensed the project under the GNU General Public License . FreeBSD and NetBSD (both derived from 386BSD ) were released as Free software when the USL v. BSDi lawsuit was settled out of court in 1993. OpenBSD forked from NetBSD in 1995. Also in 1995, The Apache HTTP Server , commonly referred to as Apache,
16899-527: Was released under the Apache License 1.0 . In 1997, Eric Raymond published The Cathedral and the Bazaar , a reflective analysis of the hacker community and Free software principles. The paper received significant attention in early 1998, and was one factor in motivating Netscape Communications Corporation to release their popular Netscape Communicator Internet suite as Free software . This code
17030-508: Was revisited in October 2008 by Amanda McPherson, Brian Proffitt, and Ron Hale-Evans. Using David A. Wheeler's methodology, they estimated redevelopment of the 2.6.25 kernel now costs $ 1.3bn (part of a total $ 10.8bn to redevelop Fedora 9). Again, Garcia-Garcia and Alonso de Magdaleno from University of Oviedo (Spain) estimate that the value annually added to kernel was about €100M between 2005 and 2007 and €225M in 2008, it would cost also more than €1bn (about $ 1.4bn as of February 2010) to develop in
17161-426: Was that distributors might add restrictions, either to the license or by combining the software with other software that had other restrictions on distribution. The union of two sets of restrictions would apply to the combined work, thus adding unacceptable constrictions. To prevent this, GPLv1 stated that modified versions, as a whole, had to be distributed under the terms of GPLv1. Therefore, software distributed under
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