View source for GNU

{{Short description|Free software collection}}
{{About|the free software collection|the animal|Wildebeest|other uses}}
{{Distinguish|XNU}}
{{Use mdy dates|date=August 2020}}
{{Use American English|date=August 2020}}
{{Infobox OS
| name = GNU
| logo = Heckert GNU white.svg
| logo size = 100px
| logo alt = The GNU head
| screenshot = Gnu hurd debian 1.png
| caption = [[Debian GNU/Hurd]] with [[Xfce4]] and web browser [[Midori (web browser)|Midori]]
| family = [[Unix-like]]
| developer = Community
| source model = [[Free software]]
| marketing target = Personal computers, mobile devices, embedded devices, servers, mainframes, supercomputers
| language = <!--Exactly which?-->
| userland = GNU
| kernel_type = [[Microkernel]] ([[GNU Hurd]]) or [[Monolithic kernel]] (GNU [[Linux-libre]], fork of [[Linux kernel|Linux]])
| license = [[GNU General Public License|GNU GPL]], [[GNU Lesser General Public License|GNU LGPL]], [[GNU Affero General Public License|GNU AGPL]], [[GNU Free Documentation License|GNU FDL]], [[GNU Project#GNU Free System Distribution Guidelines|GNU FSDG]]<ref>{{cite web | url = https://www.gnu.org/licenses/ |title = GNU Licenses}}</ref><ref>{{cite web | url = https://www.gnu.org/distros/free-system-distribution-guidelines.html |title = GNU FSDG}}</ref>
| programmed in = Various languages (notably [[C (programming language)|C]] and [[assembly language]])
| working_state = Current
| supported_platforms = [[IA-32]] (with [[Hurd]] kernel only) and [[DEC Alpha|Alpha]], [[Synopsys ARC|ARC]], [[ARM architecture family|ARM]], [[AVR32]], [[Blackfin]], [[C6x]], [[ETRAX CRIS]], [[FR-V]], [[H8/300]], [[Qualcomm Hexagon|Hexagon]], [[Itanium]], [[M32R]], [[m68k]], [[Imagination META|META]], [[MicroBlaze]], [[MIPS architecture|MIPS]], [[MN103]], [[OpenRISC]], [[PA-RISC]], [[PowerPC]], [[IB ESA/390|s390]], [[S+core]], [[SuperH]], [[SPARC]], [[TILE64]], [[Unicore32]], [[x86]], [[Xtensa]], [[RISC-V]] <!-- Do not include 64 bit extensions of 32 bit ISAs, e.g. sparc64, ppc64, x86-64 &c. --> (with [[Linux-libre]] kernel only)
}}

'''GNU''' ({{IPAc-en|audio=En-gnu.ogg|ɡ|n|uː}} {{respell|GNOO}})<ref>{{cite web | url = https://www.gnu.org/ |title = What is GNU? |work = The GNU Operating System | date = September 4, 2009 | publisher = [[Free Software Foundation]] |access-date=October 9, 2009 | quote =The name ‘GNU’ is a [[recursive acronym]] for ‘GNU's Not Unix‘; it is pronounced ''g-noo'', as one syllable with no vowel sound between the ''g'' and the ''n''.}}</ref><ref name="rms-zagreb-talk" /> is an extensive collection of [[free software]] (387 packages {{As of|2025|June|lc=y}}),<ref>{{cite web
	| url = https://www.gnu.org/software/software.html
	| title = Software – GNU Project
	| last = Stallman
	| first = Richard
	| website = GNU Project
	| access-date = 2022-01-09
	| publisher=Free Software Foundation, Inc
}}</ref> which can be used as an [[operating system]] or can be used in parts with other operating systems.<ref name="handbookonopensource" /><ref>{{cite web | url =https://www.gnu.org/gnu/manifesto.html | title = GNU Manifesto |publisher = FSF | work = GNU project |access-date= 2011-07-27}}</ref><ref>{{cite book | url= https://archive.org/details/cathedralbaz00raym | url-access= registration | title = The Cathedral & the Bazaar: Musings on Linux and Open Source by an Accidental Revolutionary | publisher= "O'Reilly Media, Inc." | pages = [https://archive.org/details/cathedralbaz00raym/page/10 10]–12 | isbn= 978-0-59600108-7 | last = Raymond | first =Eric | date = 2001-02-01}}</ref> The use of the completed GNU tools led to the family of operating systems popularly known as [[Linux]].<ref>{{Cite web|title=1.2. What is GNU/Linux?|url=https://www.debian.org/releases/stable/amd64/ch01s02.en.html|access-date=2024-06-07|website=www.debian.org}}</ref> Most of GNU is licensed under the [[GNU Project]]'s own General Public License ([[GNU General Public License|GPL]]).

[[File:Richard Stallman - Fête de l'Humanité 2014 - 010.jpg|thumb|upright|[[Richard Stallman]], founder of the GNU project]]

GNU is also the project within which the [[free software]] concept originated. [[Richard Stallman]], the founder of the project, views GNU as a "technical means to a social end".<ref>{{Citation | contribution = KTH | publisher = FSF | title = Philosophy | series = GNU | contribution-url = https://www.gnu.org/philosophy/stallman-kth.html | first = Richard | last = Stallman | type = speech | place = Stockholm, Sweden | year = 1986}}.</ref> Relatedly, [[Lawrence Lessig]] states in his introduction to the second edition of Stallman's book ''[[Free Software, Free Society]]'' that in it Stallman has written about "the social aspects of software and how Free Software can create community and social justice".<ref>{{Cite book|url=https://www.openisbn.com/isbn/9781441436856/|title=Free Software, Free Society: Selected Essays Of Richard M. Stallman|isbn=9781441436856|access-date=2016-03-24|last1=Stallman|first1=Richard M.|last2=Gay|first2=Joshua|date=December 2009|publisher=CreateSpace Independent Publishing Platform }}</ref>

== Name ==
''GNU'' is a [[recursive acronym]] for "GNU's Not Unix!",<ref name = "handbookonopensource" /><ref>{{cite web | url =https://www.thefreedictionary.com/GNU%27s+Not+Unix |title=GNU's Not Unix | publisher =The free dictionary | access-date = 2012-09-22}}</ref> chosen because GNU's design is [[Unix-like]], but differs from [[Unix]] by being free software and containing no Unix code.<ref name="handbookonopensource">{{cite book|last1=St. Amant|first1=Kirk|url=https://books.google.com/books?id=WKHuvgEACAAJ|title=Handbook of Research on Open Source Software: Technological, Economic, and Social Perspectives|last2=Still|first2=Brian|year=2007|publisher=Information Science Reference |isbn=978-1-59140999-1|oclc=1028442948}}</ref><ref>{{cite web | publisher = FSF | work = GNU project | url = https://www.gnu.org/ | title = The GNU Operating system | access-date = 2008-08-18}}</ref><ref>{{cite web|last=Marshall |first = Rosalie | place = [[Australia|AU]] | url = https://www.pcauthority.com.au/News/128513,qa-richard-stallman-founder-of-the-gnu-project-and-the-free-software-foundation.aspx |title = Q&A: Richard Stallman, founder of the GNU Project and the Free Software Foundation | publisher = PC & Tech Authority |date = 2008-11-17 |access-date = 2012-09-22}}</ref> Stallman chose the name by using various plays on words, including the song "[[The Gnu]]".<ref name="rms-zagreb-talk">{{cite AV media |url=https://mjesec.ffzg.hr/~dpavlin/stallman2006/free_software_movement_and_the_future_of_freedom_zagreb_09_march_2006.ogg |title=The Free Software Movement and the Future of Freedom |first=Richard |last=Stallman |author-link=Richard Stallman |publisher=[[Free Software Foundation Europe]] |location=Zagreb, Croatia|date=March 9, 2006 |access-date=February 20, 2007}}</ref>{{rp|at=45:30|}}

== History ==
Development of the GNU software was initiated by [[Richard Stallman]] while he worked at the [[MIT Computer Science and Artificial Intelligence Laboratory|MIT Artificial Intelligence Laboratory]]. It was called the GNU Project, and was publicly announced on September 27, 1983, on the net.unix-wizards and net.usoft [[newsgroup]]s by Stallman.<ref>{{cite newsgroup |title=new UNIX implementation |first=Richard |last=Stallman |date=September 27, 1983 |newsgroup=net.unix-wizards |message-id=771@mit-eddie.UUCP |url=https://groups.google.com/group/net.unix-wizards/msg/4dadd63a976019d7 |access-date=August 18, 2008 }}</ref> Software development began on January 5, 1984, when Stallman quit his job at the Lab so that they could not claim ownership or interfere with distributing GNU components as free software.<ref name="intervention">{{cite book |url=https://books.google.com/books?id=jXC6H8lRjlUC |title=Inter/vention: Free Play in the Age of Electracy |first1=Jan Rune |last1=Holmevik |first2=Ian |last2=Bogost |first3=Gregory |last3=Ulmer |publisher=MIT Press |date=March 2012 |isbn=978-0-262-01705-3|pages=69–71}}</ref>

The goal was to bring a completely free software operating system into existence. Stallman wanted computer users to be free to study the source code of the software they use, share software with other people, modify the behavior of software, and publish their modified versions of the software. This philosophy was published as the [[GNU Manifesto]] in March 1985.<ref>{{cite journal|url=https://www.math.utah.edu/ftp/pub/tex/bib/toc/dr-dobbs-1980.html#10(3):March:1985 |journal=Dr. Dobb's Journal of Software Tools |title=The {GNU} Manifesto |volume=10 |issue=3 |pages=30 |date=March 1985 |first=Richard |last=Stallman |author-link = Richard Stallman |access-date=2011-10-18}}</ref>

Richard Stallman's experience with the [[Incompatible Timesharing System]] (ITS),<ref name="intervention" /> an early operating system written in [[assembly language]] that became obsolete due to discontinuation of [[PDP-10]], the computer architecture for which ITS was written, led to a decision that a [[porting|portable]] system was necessary.<ref name="rms-zagreb-talk" />{{rp|at=40:52|}}<ref name="opensource2.0">{{cite book |url=https://archive.org/details/opensources2.000diborich |title=Open Sources 2.0: The Continuing Evolution |publisher="O'Reilly Media, Inc." |first1=Chris |last1=DiBona |first2=Mark |last2=Stone |first3=Danese |last3=Cooper |date=October 2005 |pages=[https://archive.org/details/opensources2.000diborich/page/n79 38]–40 |isbn=9780596008024}}</ref> It was thus decided that the development would be started using [[C (programming language)|C]] and [[Lisp (programming language)|Lisp]] as system programming languages,<ref>{{cite web|url=https://laurel.datsi.fi.upm.es/~ssoo/IG/download/timeline.html|title=Timeline of GNU/Linux and Unix|quote=Both C and Lisp will be available as system programming languages.}}</ref> and that GNU would be compatible with Unix.<ref>{{cite book |url=https://books.google.com/books?id=53zaxy423xcC|title=Beginning Portable Shell Scripting: From Novice to Professional (Expert's Voice in Open Source)|date=November 2008|pages=177–178 |isbn=9781430210436 |last1=Seebach |first1=Peter|publisher=Apress }}</ref> At the time, Unix was already a popular [[proprietary software|proprietary]] operating system. The design of Unix was modular, so it could be reimplemented piece by piece.<ref name="opensource2.0" />

Much of the needed software had to be written from scratch, but existing compatible third-party free software components were also used such as the [[TeX]] typesetting system, the [[X Window System]], and the [[Mach (kernel)|Mach]] microkernel that forms the basis of the [[GNU Mach]] core of [[GNU Hurd]] (the official kernel of GNU).<ref name="linuxinterface">{{cite book |url=https://books.google.com/books?id=Ps2SH727eCIC|title=The Linux Programming Interface: A Linux and UNIX System Programming Handbook|pages=5–6|date=October 2010 |isbn=9781593272203 |last1=Kerrisk |first1=Michael|publisher=No Starch Press }}</ref> With the exception of the aforementioned third-party components, most of GNU has been written by volunteers; some in their spare time, some paid by companies,<ref name="cygnus">{{cite book |url=https://archive.org/details/isbn_9781565925823 |title=Open Sources: Voices from the Open Source Revolution |publisher=O'Reilly & Associates, Inc. |date=January 1999 |isbn=978-1-56592-582-3 }}</ref> educational institutions, and other non-profit organizations. In October 1985, Stallman set up the [[Free Software Foundation]] (FSF). In the late 1980s and 1990s, the FSF hired software developers to write the software needed for GNU.<ref>{{cite book |url=https://books.google.com/books?id=LlCnYt2snHYC |title=The Software Industry | pages=187–196 |isbn=9783642315091 |last1=Buxmann |first1=Peter |last2=Diefenbach |first2=Heiner |last3=Hess |first3=Thomas |date=2012-09-30|publisher=Springer }}</ref><ref>{{cite book |url=https://books.google.com/books?id=50maN7VmpusC | title=Practical UNIX and Internet Security, 3rd Edition | publisher=O'Reilly & Associates, Inc. |date=February 2003 | page=18 |isbn=9781449310127}}</ref>

As GNU gained prominence, interested businesses began contributing to development or selling GNU software and technical support. The most prominent and successful of these was [[Cygnus Solutions]],<ref name="cygnus" /> now part of [[Red Hat]].<ref>{{cite web|url=https://news.cnet.com/2100-1001-232971.html|title=Red Hat buys software firm, shuffles CEO|author=Stephen Shankland|date=15 November 1999|publisher=CBS Interactive|work=CNET|access-date=5 March 2016}}</ref>

== Components ==
{{Main|List of GNU packages}}

The system's basic components include the [[GNU Compiler Collection]] (GCC), the [[GNU C library]] (glibc), and [[GNU Core Utilities]] (coreutils),<ref name="handbookonopensource" /> but also the [[GNU Debugger]] (GDB), [[GNU Binary Utilities]] (binutils),<ref>{{cite web|url=https://developer.amd.com/tools-and-sdks/archive/gcc-and-gnu-toolchains-for-amd-platforms/ |title=GCC & GNU Toolchains – AMD |publisher=Developer.amd.com |access-date=2015-09-02 |archive-url=https://web.archive.org/web/20150316191013/https://developer.amd.com/tools-and-sdks/archive/gcc-and-gnu-toolchains-for-amd-platforms/ |archive-date=2015-03-16 }}</ref> and the [[Bash (Unix shell)|GNU Bash]] shell.<ref name="linuxinterface" /><ref>{{cite book| chapter-url=https://books.google.com/books?id=vvuzDziOMeMC|title=Beginning Linux Programming|chapter=The GNU Project and the Free Software Foundation| isbn=9781118058619| last1=Matthew| first1=Neil| last2=Stones| first2=Richard| date=2011-04-22|publisher=John Wiley & Sons }}</ref><ref>{{cite book| url=https://books.google.com/books?id=7MhTb9X4aYgC|title=Emerging Free and Open Source Software Practices|pages=262–264|date=May 2007| isbn=9781599042107| last1=Sowe| first1=Sulayman K| last2=Stamelos| first2=Ioannis G| last3=Samoladas| first3=Ioannis M|publisher=Idea Group Inc (IGI) }}</ref> GNU developers have contributed to Linux [[port (software)|port]]s of GNU applications and utilities, which are now also widely used on other operating systems such as [[Berkeley Software Distribution|BSD]] variants, [[Solaris (operating system)|Solaris]] and [[macOS]].<ref>{{cite web |url=https://www.buzzle.com/articles/linux-history-and-introduction.html |title=Linux: History and Introduction |publisher=Buzzle.com |date=1991-08-25 |access-date=2012-09-22 |archive-url=https://web.archive.org/web/20171211040818/https://www.buzzle.com/articles/linux-history-and-introduction.html |archive-date=2017-12-11 |url-status=usurped }}</ref>{{better source needed|date=May 2018}}

Many GNU programs have been ported to other operating systems, including [[proprietary software|proprietary]] platforms such as [[Microsoft Windows]]<ref>{{cite book| url=https://books.google.com/books?id=0SM3PEH9gagC|title=Integrating Linux and Windows|page=30|date=December 2000| isbn=9780130306708| last1=McCune| first1=Mike|publisher=Prentice Hall Professional }}</ref> and macOS.<ref>{{cite book| url=https://books.google.com/books?id=o9K8KEQic5sC|title=A Practical Guide To Unix For Mac Os X Users|page=4|year=2005| isbn=9780131863330| last1=Sobell| first1=Mark G| last2=Seebach| first2=Peter|publisher=Prentice Hall Professional }}</ref> GNU programs have been shown to be more reliable than their proprietary Unix counterparts.<ref>[https://ftp.cs.wisc.edu/pub/paradyn/technical_papers/fuzz-revisited.ps Fuzz Revisited: A Re-examination of the Reliability of UNIX Utilities and Services] – October 1995 – Computer Sciences Department, University of Wisconsin</ref><ref>{{Cite web|url=https://pages.cs.wisc.edu/~blbowers/fuzz-2001.pdf |archive-url=https://web.archive.org/web/20091222035742/http://pages.cs.wisc.edu/~blbowers/fuzz-2001.pdf |archive-date=2009-12-22 |url-status=live|title=An Inquiry into the Stability and Reliability of UNIX Utilities}}</ref>

{{As of|2024|June}}, there are a total of 467 GNU packages (including decommissioned, 394 excluding) hosted on the official GNU development site.<ref>{{cite web|url=https://www.gnu.org/software/software.html |title=Software – GNU Project|publisher=Free Software Foundation, Inc |date=2016-01-13 |access-date=2016-01-13}}</ref>

==GNU as an operating system==
{{Main|GNU variants}}

In its [[History of operating systems#Background|original meaning]], and one still common in hardware engineering, the operating system is a basic set of functions to control the hardware and manage things like [[task scheduler|task scheduling]] and [[system call]]s. In modern terminology used by software developers, the collection of these functions is usually referred to as a [[operating system kernel|kernel]], while an 'operating system' is expected to have a more extensive set of programs. The GNU project maintains two kernels itself, allowing the creation of pure GNU operating systems, but the GNU toolchain is also used with non-GNU kernels. Due to the two different definitions of the term 'operating system', there is an ongoing [[GNU/Linux naming controversy|debate concerning the naming of distributions of GNU packages with a non-GNU kernel]]. (See below.)

=== With kernels maintained by GNU and FSF ===
[[File:Parabola12.png|thumb|[[Parabola GNU/Linux-libre]], an example of an FSF approved distribution that uses a [[rolling release]] model]]

==== GNU Hurd ====
The original kernel of GNU Project is the [[GNU Hurd]] (together with the [[GNU Mach]] microkernel), which was the original focus of the [[Free Software Foundation]] (FSF).<ref name = "handbookonopensource" /><ref name = computerworld>Vaughan-Nichols, Steven J. "[https://www.computerworld.com/s/article/9131178/Opinion_The_top_10_operating_system_stinkers Opinion: The top 10 operating system stinkers]", ''[[Computerworld]]'', April 9, 2009: "... after more than 25 years in development, GNU remains incomplete: its kernel, Hurd, has never really made it out of the starting blocks. ... Almost no one has actually been able to use the OS; it's really more a set of ideas than an operating system."</ref><ref name= Hillesley>{{Citation | last = Hillesley | first = Richard | newspaper = The H | url = https://www.h-online.com/open/features/GNU-HURD-Altered-visions-and-lost-promise-1030942.html | edition = online | title = GNU HURD: Altered visions and lost promise | date = June 30, 2010 | page = [https://www.h-online.com/open/features/GNU-HURD-Altered-visions-and-lost-promise-1030942.html?page=3 3] | quote = Nearly twenty years later the HURD has still to reach maturity, and has never achieved production quality. ... Some of us are still wishing and hoping for the real deal, a GNU operating system with a GNU kernel.}}</ref><ref>{{cite book |last1=Lessig |first1=Lawrence |title=The Future of Ideas: The Fate of the Commons in a Connected World |date=2001 |publisher=Random House |isbn=978-0-375-50578-2 |url=https://archive.org/details/futureo_les_2001_00_1645|url-access=registration |page=[https://archive.org/details/futureo_les_2001_00_1645/page/54 54] |quote=He had mixed all of the ingredients needed for an operating system to function, but he was missing the core.}}</ref>

With the April 30, 2015 release of the Debian GNU/Hurd 2015 distro,<ref>{{Cite web|url=https://www.phoronix.com/scan.php?page=news_item&px=Debian-GNU-Hurd-2015|title=Debian GNU/Hurd 2015 Released – Phoronix|website=www.phoronix.com|access-date=2016-03-24}}</ref><ref>{{Cite web|url=https://lists.debian.org/debian-hurd/2015/04/msg00047.html|title=Debian GNU/Hurd 2015 released!|website=lists.debian.org|access-date=2016-03-24}}</ref> GNU now provides all required components to assemble an operating system that users can install and use on a computer.<ref name="status">{{Cite web|url=https://www.gnu.org/software/hurd/hurd/status.html|title=status|website=www.gnu.org|access-date=2016-03-24}}</ref><ref>{{Cite web|url=https://www.debian.org/ports/hurd/|title=Debian – Debian GNU/Hurd|website=www.debian.org|access-date=2016-03-24}}</ref><ref>{{Cite web|url=https://www.debian.org/ports/hurd/hurd-install|title=Debian – Debian GNU/Hurd – Configuration|website=www.debian.org|access-date=2016-03-24}}</ref>

However, the Hurd kernel is not yet considered production-ready but rather a base for further development and non-critical application usage.<ref>{{Citation | url=https://www.gnu.org/software/hurd/hurd/status.html | publisher = Free Software Foundation | title = Status | access-date = 2017-04-24 | date = 2015-05-03}}</ref><ref name="status" />

==== Linux-libre ====
In 2012, a fork of the [[Linux kernel]] became officially part of the GNU Project in the form of [[Linux-libre]], a variant of Linux with all proprietary components removed.<ref>{{cite web | url= https://directory.fsf.org/wiki/GNU_Linux-libre |title = GNU Linux-libre | date = 2012-12-17 | access-date = 2013-02-09}}</ref>
The GNU Project has endorsed Linux-libre distributions, such as [[Trisquel]], [[Parabola GNU/Linux-libre]], [[PureOS]] and [[GNU Guix System]].<ref>{{Citation | contribution-url = https://www.gnu.org/distros/free-distros.html | contribution = List of Free GNU/Linux Distributions | title = GNU Project | publisher = Free Software Foundation (FSF)}}.</ref>

=== With non-GNU kernels ===
[[File:Trisquel 11.0.png|thumb|[[Trisquel]], an example of an [[List of GNU/Linux distributions endorsed by the Free Software Foundation|FSF approved distribution]]]]

Because of the development status of Hurd, GNU is usually paired with other kernels such as [[Linux]]<ref>{{Citation | chapter-url = https://oreilly.com/openbook/debian/book/ch01_02.html |title= Debian open book | chapter = 1.2 What is Linux? |publisher = O'Reilly |date=1991-10-05 |access-date = 2012-09-22}}</ref><ref>{{Citation | edition = 12.4 | contribution-url = https://help.ubuntu.com/lts/installation-guide/armhf/ch01s03.html | contribution = What is GNU/Linux? | publisher = Canonical | title = Ubuntu Installation Guide | access-date = 2015-06-22 | archive-date = June 21, 2015 | archive-url = https://web.archive.org/web/20150621214422/https://help.ubuntu.com/lts/installation-guide/armhf/ch01s03.html | url-status = dead }}</ref> or [[FreeBSD]].<ref>{{cite book|url=https://books.google.com/books?id=CHkHNChvPqIC |title=Open Source Software: Implementation and Management| page = 129| isbn= 978-1-55558320-0| last1 = Kavanagh | first1 = Paul| date = 2004-07-26|publisher=Elsevier }}</ref> Whether the combination of GNU libraries with external kernels is a GNU operating system with a kernel (e.g. GNU with Linux), because the GNU collection renders the kernel into a usable operating system as understood in modern software development, or whether the kernel is an operating system unto itself with a GNU layer on top (i.e. Linux with GNU), because the kernel can operate a machine without GNU, is a matter of ongoing debate. The FSF maintains that an operating system built using the [[Linux kernel]] and GNU tools and utilities should be considered a [[GNU variants|variant of GNU]], and promotes the term ''GNU/Linux'' for such systems (leading to the [[GNU/Linux naming controversy]]). This view is not exclusive to the FSF.<ref>{{cite newsgroup | url = https://groups.google.com/group/comp.os.linux.misc/msg/1241a2919efc4bc3 | title = Linux is a GNU system and the DWARF support | newsgroup = comp.os.linux.misc | date = 8 September 1994 | first = Matt | last = Welsh | access-date = 3 February 2008 | quote = RMS's idea (which I have heard first-hand) is that Linux systems should be considered GNU systems with Linux as the kernel.}}</ref><ref>{{cite web|last=Proffitt |first = Brian |url=https://www.itworld.com/it-managementstrategy/285750/debian-gnulinux-seeks-alignment-free-software-foundation | title =Debian GNU/Linux seeks alignment with Free Software Foundation | work =ITworld | date =2012-07-12 |access-date= 2012-09-22}}</ref><ref>{{cite web|url= https://www.tldp.org/LDP/sag/html/gnu-or-not.html |title= 1.1. Linux or GNU/Linux, that is the question | work = SAG | publisher= TLDP | access-date = 2012-09-22}}</ref><ref>{{Cite web|url=https://ccm.net/faq/478-gnu-operating-system|title=GNU Operating System – CCM FAQ|website=CCM|language=en|access-date=2018-04-08|quote=GNU is an operating system that offers a set of free open source programs.|archive-date=December 15, 2019|archive-url=https://web.archive.org/web/20191215074114/https://ccm.net/faq/478-gnu-operating-system|url-status=dead}}</ref><ref>{{Cite web|url=https://www.snom.com/footer/source-code-gpl-open-source/|title=Source Code & GPL Open Source|last=Snom Technology|website=www.snom.com|language=en|access-date=2018-04-08|quote=Variants of the GNU operating system, which use the kernel Linux, are now widely used; though these systems are often referred to as "Linux", they are more accurately called "GNU/Linux systems".|archive-date=April 9, 2018|archive-url=https://web.archive.org/web/20180409044219/https://www.snom.com/footer/source-code-gpl-open-source/|url-status=dead}}</ref> Notably, [[Debian]], one of the biggest and oldest Linux distributions, refers to itself as ''Debian GNU/Linux''.<ref>{{cite web| url = https://www.debian.org/doc/manuals/debian-faq/basic-defs.en.html#whatisdebian| title = Chapter 1. Definitions and overview}}</ref>

== Copyright, GNU licenses, and stewardship ==
The GNU Project recommends that contributors assign the copyright for GNU packages to the Free Software Foundation,<ref>{{cite web| url = https://www.gnu.org/prep/maintain/html_node/Copyright-Papers.html |title=Copyright Papers | work = Information For Maintainers of GNU Software |publisher= FSF |date=2011-06-30 | access-date =2011-07-27}}</ref><ref>{{cite web | work = GNU | url= https://www.gnu.org/licenses/why-assign.html |title=Why the FSF gets copyright assignments from contributors | publisher = FSF | date= 2011-07-15 | access-date = 2011-07-27}}</ref> though the Free Software Foundation considers it acceptable to release small changes to an existing project to the [[public domain]].<ref>{{cite web | work = GNU | url = https://www.gnu.org/licenses/license-recommendations.html |publisher = Free Software Foundation |title=How to choose a license for your own work | access-date =2012-07-12}}</ref> However, this is not required; package maintainers may retain copyright to the GNU packages they maintain, though since only the copyright holder may enforce the license used (such as the GNU GPL), the copyright holder in this case enforces it rather than the Free Software Foundation.<ref>{{cite web | last = Raymond | first = Eric S | url = https://www.catb.org/esr/Licensing-HOWTO.html | title = Licensing HOWTO | publisher = CatB | date = 2002-11-09 | access-date = 2012-09-22 | archive-date = February 15, 2022 | archive-url = https://web.archive.org/web/20220215060436/https://www.catb.org/esr/Licensing-HOWTO.html | url-status = dead }}</ref>

For the development of needed software, Stallman wrote a license called the [[GNU General Public License]] (first called Emacs General Public License), with the goal to guarantee users freedom to share and change free software.<ref>{{Citation | title = Old licenses | series = GNU | publisher = FSF | contribution-url = https://www.gnu.org/licenses/old-licenses/gpl-1.0.txt | contribution = GPL 1.0}}.</ref> Stallman wrote this license after his experience with [[James Gosling]] and a program called UniPress, over a controversy around software code use in the [[GNU Emacs]] program.<ref name = "twobits">{{cite book|chapter-url= https://books.google.com/books?id=MEmMl-tY8jEC | title = Two Bits: The Cultural Significance of Free Software | chapter = Writing Copyright Licenses | date =June 2008|isbn = 978-0-82234264-9 | last = Kelty | first = Christopher M| publisher = Duke University Press }}</ref><ref>{{Citation | url = https://www.free-soft.org/gpl_history/ | title = The History of the GNU General Public License | publisher = Free Software}}.</ref> For most of the 80s, each GNU package had its own license: the Emacs General Public License, the GCC General Public License, etc. In 1989, FSF published a single license they could use for all their software, and which could be used by non-GNU projects: the [[GNU General Public License]] (GPL).<ref name="twobits" /><ref>{{Citation | url = https://www.gnu.org/bulletins/bull5.html#SEC7 | date = Jun 11, 1998 | title = GNU's flashes | newspaper = GNU's Bulletin | volume = 1 | number = 5 | series = GNU Project | publisher = Free Software Foundation (FSF)}}.</ref>

This license is now used by most of GNU software, as well as a large number of free software programs that are not part of the GNU Project; it also historically has been the most commonly used [[free software license]] (though recently challenged by the [[MIT license]]).<ref>{{cite web |url = https://osrc.blackducksoftware.com/data/licenses |title = Open Source License Data |work = Open Source Resource Center |publisher = Black Duck Software |access-date = September 24, 2012 |url-status = dead |archive-url = https://web.archive.org/web/20121008170109/https://osrc.blackducksoftware.com/data/licenses/ |archive-date = October 8, 2012 }}</ref><ref>{{cite web |url = https://resources.whitesourcesoftware.com/blog-whitesource/top-open-source-licenses-trends-and-predictions |title= Top Open Source Licenses in 2020: Trends and predictions |publisher = WhiteSource Software |access-date = February 19, 2020 |archive-url = https://web.archive.org/web/20200219122556/https://resources.whitesourcesoftware.com/blog-whitesource/top-open-source-licenses-trends-and-predictions |archive-date = February 19, 2020 }}</ref> It gives all recipients of a program the right to run, copy, modify and distribute it, while forbidding them from imposing further restrictions on any copies they distribute. This idea is often referred to as [[copyleft]].<ref>{{cite book|url= https://books.google.com/books?id=c7ppFih2mSwC | title = Decoding Liberation: The Promise of Free and Open Source Software|pages= 46–52|date = August 2007|isbn=978-0-41597893-4| last1 = Chopra |first1 = Samir| last2 = Dexter | first2 = Scott| publisher = Routledge}}</ref>

In 1991, the [[GNU Lesser General Public License]] (LGPL), then known as the Library General Public License, was written for the [[GNU C Library]] to allow it to be linked with proprietary software.<ref>{{Citation | publisher = Free BSD | url = https://www.freebsd.org/doc/en_US.ISO8859-1/articles/bsdl-gpl/origins-lgpl.html | title = The origins of Linux and the LGPL}}.</ref> 1991 also saw the release of version 2 of the GNU GPL. The [[GNU Free Documentation License]] (FDL), for documentation, followed in 2000.<ref>{{cite book|url= https://books.google.com/books?id=2VElII9QeakC | title = Innovation Happens Elsewhere: Open Source as Business Strategy| pages = 133–34| date = April 2005 | isbn = 978-1-55860889-4| last1 = Goldman | first1 = Ron| last2= Gabriel | first2 = Richard P| publisher = Morgan Kaufmann}}</ref> The GPL and LGPL were revised to version 3 in 2007, adding clauses to protect users against hardware restrictions that prevent users from running modified software on their own devices.<ref>{{cite book |chapter-url= https://books.google.com/books?id=gmfFsdIAejkC | title = Linux Essentials |chapter = Free Software and the GPL |year=2012 |isbn = 978-1-11819739-4 |last1=Smith |first1 = Roderick W| publisher = John Wiley & Sons }}</ref>

Besides GNU's packages, the GNU Project's licenses can<ref>{{Cite web |title=Frequently Asked Questions about the GNU Licenses |url=https://www.gnu.org/licenses/gpl-faq.html#DoesUsingTheGPLForAProgramMakeItGNUSoftware |access-date=May 11, 2023 |website=Gnu project}}</ref> and are used by many unrelated projects, such as the [[Linux kernel]], often used with GNU software. A majority of free software such as the X Window System,<ref>{{Cite web |date=2014-08-25 |title=COPYING · master · xorg / xserver · GitLab |url=https://gitlab.freedesktop.org/xorg/xserver/-/blob/master/COPYING |access-date=2023-07-18 |website=GitLab |language=en}}</ref> is licensed under [[permissive free software license]]s.<ref>{{Cite web |title=Permissive vs. copyleft open source licenses 2021 |url=https://www.statista.com/statistics/1245665/worldwide-permissive-copyleft-open-source-licenses/ |access-date=2023-07-18 |website=Statista |language=en}}</ref>

== Logo ==
[[File:Official gnu.svg|thumb|The original GNU logo, drawn by Etienne Suvasa|120px]]
The logo for GNU is a [[wildebeest|gnu]] head. Originally drawn by Etienne Suvasa, a bolder and simpler version designed by Aurelio Heckert is now preferred.<ref>{{cite web|url=https://www.gnu.org/graphics/agnuhead.html |title=A GNU Head |publisher= Free Software Foundation (FSF)|date=2011-07-13 |access-date=2011-07-27}}</ref><ref>{{cite web|url=https://www.gnu.org/graphics/heckert_gnu.html |title=A Bold GNU Head |publisher=[[Free Software Foundation]]|date=2011-07-13 |access-date=2011-07-27}}</ref> It appears in GNU software and in printed and electronic documentation for the GNU Project, and is also used in Free Software Foundation materials.

[[File:Gnu-30-banner-without-background.svg|thumb|30th anniversary logo|120px|left]]
There was also a modified version of the official logo. It was created by the [[Free Software Foundation]] in September 2013 in order to commemorate the 30th anniversary of the [[GNU Project]].<ref>{{cite web|url=https://www.gnu.org/gnu30/ |title=GNU 30th Anniversary |publisher=[[Free Software Foundation]]|date=2013-10-08 |access-date=2014-12-15}}</ref>
{{clear}}

== See also ==
{{Portal|Free and open-source software}}
<!-- Please keep entries in alphabetical order. -->
* [[Free software movement]]
* [[History of free and open-source software]]
* [[List of computing mascots]]
* [[:Category:Computing mascots]]

== References ==
{{Reflist|30em}}

== External links ==
{{Commons}}

* {{Official website}}
* {{webarchive |url=https://web.archive.org/web/20001025040323/http://prep.ai.mit.edu |title=The GNU Project web server, prep.ai.mit.edu}}
* [https://unxutils.sf.net unxutils.sourceforge.net, Ports of GNU utilities] for [[Microsoft Windows]]
* {{webarchive |url=https://web.archive.org/web/20170629022841/https://www.verbumvanum.org/pesalus/ |title=www.verbumvanum.org/pesalus, The daemon, the GNU and the penguin}}

{{Unix-like}}
{{GNU}}
{{FLOSS}}
{{Operating systems}}
{{Authority control}}

[[Category:Free software operating systems]]
[[Category:GNU Project]]
[[Category:Mach (kernel)]]
[[Category:Microkernel-based operating systems]]
[[Category:Unix variants]]
[[Category:Computing acronyms]]