Editing GNU (section)

== 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}}</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>