<!--#include virtual="/server/header.html" --> <!-- Parent-Version: 1.96 --> <!-- This page is derived from /server/standards/boilerplate.html --> <title>Licenses - GNU Project - Free Software Foundation</title> <!--#include virtual="/licenses/po/licenses.translist" --> <!--#include virtual="/server/banner.html" --> <h2>Licenses</h2><hr class="thin" /><div class="thin"></div> <div class="summary"> <h3 class="no-display">Table of Contents</h3> <ul> <li><a href="#Evaluation">Evaluating Licenses</a></li> <li><a href="#CommonResources">Common Resources for our Software Licenses</a></li> <li><a href="#GPL">The GNU General Public License</a></li> <li><a href="#LGPL">The GNU Lesser General Public License</a></li> <li><a href="#AGPL">The GNU Affero General Public License</a></li> <li><a href="#FDL">The GNU Free Documentation License</a></li> <li><a href="#Exceptions">Exceptions to GNU Licenses</a></li> <li><a href="#LicenseURLs">License URLs</a></li> <li><a href="#UnofficialTransl">Unofficial Translations</a></li> <li><a href="#VerbatimCopying">Verbatim Copying and Distribution</a></li> <li><a href="#FSLicenses">List of Free Software Licenses</a></li> <li><a href="#WhatIsCopyleft">What Is Copyleft?</a></li> <li><a href="#OtherWorks">Licenses for Other Types of Works</a></li> </ul> <hr class="no-display" /> </div><div style="width: 47em; max-width: 100%"><p> Published software should be <a href="/philosophy/free-sw.html">free software</a>. To make it free software, you need to release it under a free software license. We normally use the <a href="#GPL">GNU General Public License</a> (GNU GPL), specifying version 3 or any later version, but occasionally we use <a href="/licenses/license-list.html#SoftwareLicenses">other free software licenses</a>. We use only licenses that are compatible with the GNU GPL for GNU software. </p> <p> Documentation for free software should be <a href="/philosophy/free-doc.html">free documentation</a>, so that people can redistribute it and improve it along with the software it describes. To make it free documentation, you need to release it under a free documentation license. We normally use the <a href="#FDL">GNU Free Documentation License</a> (GNU FDL), but occasionally we use <a href="/licenses/license-list.html#DocumentationLicenses">other free documentation licenses</a>. </p> <p>If you've started a new project and you're not sure what license to use, <a href="/licenses/license-recommendations.html">“How to choose a license for your own work”</a> details our recommendations in an easy-to-follow guide. If you just want a quick list reference, we have a page that names our <a href="/licenses/recommended-copylefts.html">recommended copyleft licenses</a>.</p> <p>We also have a page that discusses <a href="/licenses/bsd.html">the BSD License Problem</a>.</p> <div style="width: 47em; max-width: 100%"> <h3 id="Evaluation">Evaluating Licenses</h3> <p>If you come across a license not mentioned in our <a href="/licenses/license-list.html">license list</a>, you can ask us to evaluate whether it is a free license. Please email a copy of the license (and the URL where you found it) to <a href="mailto:licensing@fsf.org">licensing@fsf.org</a>. Our licensing experts in the staff and the board of directors will review it. If the license has some unusual conditions, they may pose difficult philosophical problems, so we can't promise to decide quickly.</p> <h3 id="CommonResources">Common Resources for our Software Licenses</h3> <p>We have a number of resources to help people understand and use our various licenses:</p> <ul> <li><a href="/licenses/gpl-faq.html">Frequently Asked Questions about the GNU licenses</a></li> <li><a href="/licenses/gpl-howto.html">How to use GNU licenses for your own software</a></li> <li><a href="/licenses/gpl-violation.html">What to do if you see a violation of a GNU license</a></li> <li><a href="/licenses/license-compatibility.html">License Compatibility and Relicensing</a></li> <li><a href="/licenses/license-list.html">List of Free Software Licenses</a></li> <li><a href="/philosophy/university.html">Releasing Free Software if you work at a university</a></li> <li><a href="/licenses/why-assign.html">Why the FSF gets copyright assignments from contributors</a></li> <li><a href="/graphics/license-logos.html">GNU license logos</a> to use with your project</li> <li><ahref="http://www.fsf.org/licensing">Thehref="https://www.fsf.org/licensing">The FSF Licensing & Compliance Lab</a></li> <li><a href="/licenses/license-list.html#LicensingEmailAddress"><licensing@fsf.org></a> for general licensing help </li> </ul> <h3 id="GPL">The GNU General Public License</h3> <p> The GNU General Public License is often called the GNU GPL for short; it is used by most GNU programs, and by more than half of all free software packages. The latest version is version 3. </p> <ul> <li>The GNU General Public License is available in these formats: <a href="/licenses/gpl.html">HTML</a>, <a href="/licenses/gpl.txt">plain text</a>, <a href="/licenses/gpl.odt">ODF</a>, Docbook <a href="/licenses/gpl.dbk">v4</a> or <a href="/licenses/gpl.xml">v5</a>, <a href="/licenses/gpl.texi">Texinfo</a>, <a href="/licenses/gpl.tex">LaTeX</a>, <a href="/licenses/gpl.md">Markdown</a>, and <a href="/licenses/gpl.rtf">RTF</a>. These documents are not formatted for standalone publishing, and are intended to be included in another document.</li> <li><a href="/licenses/quick-guide-gplv3.html">A Quick Guide to GPLv3</a></li> <li><a href="/licenses/old-licenses/old-licenses.html#GPL">Older versions of the GNU GPL</a></li> </ul> <h3 id="LGPL">The GNU Lesser General Public License</h3> <p> The GNU Lesser General Public License is used by a few (not by any means all) GNU libraries. The latest version is version 3. </p> <ul> <li>The GNU Lesser General Public License text is available in these formats: <a href="/licenses/lgpl.html">HTML</a>, <a href="/licenses/lgpl.txt">plain text</a>, <a href="/licenses/lgpl.dbk">Docbook</a>, <a href="/licenses/lgpl.texi">Texinfo</a>, <a href="/licenses/lgpl.md">Markdown</a>, <a href="/licenses/lgpl.odt">ODF</a>, and <a href="/licenses/lgpl.rtf">RTF</a>. These documents are not formatted for standalone publishing, and are intended to be included in another document.</li> <li><a href="/licenses/why-not-lgpl.html">Why you shouldn't use the Lesser GPL for your next library</a></li> <li><a href="/licenses/old-licenses/old-licenses.html#LGPL">Older versions of the GNU LGPL</a></li> </ul> <h3 id="AGPL">The GNU Affero General Public License</h3> <p> The GNU Affero General Public License is based on the GNU GPL, but has an additional term to allow users who interact with the licensed software over a network to receive the source for that program. We recommend that people consider using the GNU AGPL for any software which will commonly be run over a network. The latest version is version 3. </p> <ul> <li>The GNU Affero General Public License text is available in these formats: <a href="/licenses/agpl.html">HTML</a>, <a href="/licenses/agpl.txt">plain text</a>, <a href="/licenses/agpl.dbk">Docbook</a>, <a href="/licenses/agpl.texi">Texinfo</a>, <a href="/licenses/agpl.tex">LaTeX</a>, <a href="/licenses/agpl.md">Markdown</a>, <a href="/licenses/agpl.odt">ODF</a>, and <a href="/licenses/agpl.rtf">RTF</a>. These documents are not formatted for standalone publishing, and are intended to be included in another document.</li> <li><a href="/licenses/why-affero-gpl.html">Why the Affero GPL</a></li> </ul> <h3 id="FDL">The GNU Free Documentation License</h3> <p> The GNU Free Documentation License is a form of copyleft intended for use on a manual, textbook or other document to assure everyone the effective freedom to copy and redistribute it, with or without modifications, either commercially or non-commercially. The latest version is 1.3. </p> <ul> <li>The GNU Free Documentation License text is available in these formats: <a href="/licenses/fdl.html">HTML</a>, <a href="/licenses/fdl.txt">plain text</a>, Docbook <a href="/licenses/fdl.xml">v4</a> or <a href="/licenses/fdl-db5.xml">v5</a>, <a href="/licenses/fdl.texi">Texinfo</a>, <a href="/licenses/fdl.tex">LaTeX</a>, <a href="/licenses/fdl.md">Markdown</a>, <a href="/licenses/fdl.odt">ODF</a>, and <a href="/licenses/fdl.rtf">RTF</a>. These documents are not formatted for standalone publishing, and are intended to be included in another document.</li> <li><a href="/licenses/why-gfdl.html">Why publishers should use the GNU FDL</a></li> <li><a href="/licenses/fdl.html#addendum">How to use the GNU FDL for your documentation</a></li> <li><a href="/licenses/fdl-howto.html">Tips on using the GNU FDL</a></li> <li><a href="/licenses/fdl-howto-opt.html">How to use the optional features of the GNU FDL</a></li> <li><a href="/licenses/old-licenses/old-licenses.html#FDL"> Older versions of the GNU FDL</a></li> </ul> <h3 id="Exceptions">Exceptions to GNU Licenses</h3> <p>Some GNU programs have additional permissions or special exceptions to specific terms in one of the main licenses. Since some of those are commonly used or inspire a lot of questions on their own, we've started collecting them on our <a href="/licenses/exceptions.html">exceptions page</a>.</p> <h3 id="LicenseURLs">License URLs</h3> <p>When linking to our licenses, it's usually best to link to the latest version; hence the standard URLs such as<code>http://www.gnu.org/licenses/gpl.html</code><code>https://www.gnu.org/licenses/gpl.html</code> have no version number. Occasionally, however, you may want to link to a specific version of a given license. In those situations, you can use the following links [<a href="#urlskip">skip links</a>]:</p> <dl> <dt>GNU General Public License (GPL)</dt> <!-- Please keep these links absolute. I'm depending on that for the XSLT to generate pages on fsf.org. Thanks. -brett --> <dd><ahref="http://www.gnu.org/licenses/gpl-3.0.html">GPLv3</a>,href="/licenses/gpl-3.0.html">GPLv3</a>, <ahref="http://www.gnu.org/licenses/gpl-2.0.html">GPLv2</a>,href="/licenses/gpl-2.0.html">GPLv2</a>, <ahref="http://www.gnu.org/licenses/gpl-1.0.html">GPLv1</a></dd>href="/licenses/gpl-1.0.html">GPLv1</a></dd> <dt>GNU Lesser General Public License (LGPL)</dt> <dd><ahref="http://www.gnu.org/licenses/lgpl-3.0.html">LGPLv3</a>,href="/licenses/lgpl-3.0.html">LGPLv3</a>, <ahref="http://www.gnu.org/licenses/lgpl-2.1.html">LGPLv2.1</a></dd>href="/licenses/lgpl-2.1.html">LGPLv2.1</a></dd> <dt>GNU Affero General Public License (AGPL)</dt> <dd><ahref="http://www.gnu.org/licenses/agpl-3.0.html">GNUhref="/licenses/agpl-3.0.html">GNU AGPLv3</a> (The <a href="https://web.archive.org/web/20190826200024/http://www.affero.org/oagpl.html">Affero General Public License version 1</a> is not a GNU license, but it was designed to serve a purpose much like the GNU AGPL's.)</dd> <dt>GNU Free Documentation License (FDL)</dt> <dd><ahref="http://www.gnu.org/licenses/fdl-1.3.html">FDLv1.3</a>,href="/licenses/fdl-1.3.html">FDLv1.3</a>, <ahref="http://www.gnu.org/licenses/fdl-1.2.html">FDLv1.2</a>,href="/licenses/fdl-1.2.html">FDLv1.2</a>, <ahref="http://www.gnu.org/licenses/fdl-1.1.html">FDLv1.1</a></dd>href="/licenses/fdl-1.1.html">FDLv1.1</a></dd> </dl> <p id="urlskip">Stable links to each license's alternative formats are available on its respective page. Not every version of every license is available in every format. If you need one that is missing, please <a href="mailto:licensing@gnu.org">email us</a>.</p> <p>See also the <ahref="old-licenses/">oldhref="/licenses/old-licenses/">old licenses page</a>.</p> <h3 id="UnofficialTransl">Unofficial Translations</h3> <p> Legally speaking, the original (English) version of the licenses is what specifies the actual distribution terms for GNU programs and others that use them. But to help people better understand the licenses, we give others permission to publish unofficial translations into otherlanguageslanguages, provided that they follow our regulations for unofficialtranslations:translations. </p> <p> The FSF does not approve license translations as officially valid. The reason is that checking them would be difficult and expensive (needing the help of bilingual lawyers in other countries). Even worse, if an error did slip through, the results could be disastrous for the whole free software community. As long as the translations are unofficial, they can't do any legal harm.</p> <p>To underscore the fact that these translations are not officially valid, we do not publish translations. To make that clear, we don't post them on gnu.org, or on other GNU and FSF web sites; we only link to them.</p> <ul> <li> <a href="/licenses/translations.html">List of unofficial translations</a> </li> <li><a href="/licenses/translations.html#rules">How to create an unofficial translation</a></li> </ul> <h3 id="VerbatimCopying">Verbatim Copying and Distribution</h3> <p>The standard copyright terms for GNU web pages is now the <ahref="http://creativecommons.org/licenses/by-nd/4.0/">Creativehref="https://creativecommons.org/licenses/by-nd/4.0/">Creative Commons Attribution-NoDerivs 4.0 International License</a>. It used to be (and for a few pages still is):</p> <blockquote><p>Verbatim copying and distribution of this entire article are permitted worldwide, without royalty, in any medium, provided this notice is preserved.</p></blockquote> <p>Please note the following commentary about this “verbatim license” by Eben Moglen:</p> <blockquote><p> “Our intention in using the phrase ‘verbatim copying in any medium’ is not to require retention of page headings and footers or other formatting features. Retention of weblinks in both hyperlinked and non-hyperlinked media (as notes or some other form of printed URL in non-HTML media) is required.” </p></blockquote> <h3 id="FSLicenses">List of Free Software Licenses</h3> <ul> <li> <a href="/licenses/license-list.html">List of Free Software Licenses</a> <p> If you are contemplating writing a new license, please contact the FSF by writing to <a href="mailto:licensing@fsf.org"><licensing@fsf.org></a>. The proliferation of different free software licenses means increased work for users in understanding the licenses; we may be able to help you find an existing Free Software license that meets your needs. </p> <p> If that isn't possible, if you really need a new license, with our help you can ensure that the license really is a Free Software license and avoid various practical problems. </p> </li> </ul> <h3 id="WhatIsCopyleft">What Is Copyleft?</h3> <p> <a href="/licenses/copyleft.html"><em>Copyleft</em></a> is a general method for making a program free software and requiring all modified and extended versions of the program to be free software as well. </p> <p> The simplest way to make a program free is to put it in the <a href="/philosophy/categories.html#PublicDomainSoftware">public domain</a>, uncopyrighted. This allows people to share the program and their improvements, if they are so minded. But it also allows uncooperative people to convert the program into <a href="/philosophy/categories.html#ProprietarySoftware">proprietary software</a>. They can make changes, many or few, and distribute the result as a proprietary product. People who receive the program in that modified form do not have the freedom that the original author gave them; the middleman has stripped it away. </p> <p> In the <a href="/gnu/thegnuproject.html">GNU project</a>, our aim is to give <em>all</em> users the freedom to redistribute and change GNU software. If middlemen could strip off the freedom, we might have many users, but those users would not have freedom. So instead of putting GNU software in the public domain, we “copyleft” it. Copyleft says that anyone who redistributes the software, with or without changes, must pass along the freedom to further copy and change it. Copyleft guarantees that every user has freedom. </p> <p> Copyleft also provides an <a href="/philosophy/pragmatic.html">incentive</a> for other programmers to add to free software. Important free programs such as the GNU C++ compiler exist only because of this. </p> <p> Copyleft also helps programmers who want to contribute <a href="/software/software.html#develop">improvements</a> to <a href="/philosophy/free-sw.html">free software</a> get permission to do that. These programmers often work for companies or universities that would do almost anything to get more money. A programmer may want to contribute her changes to the community, but her employer may want to turn the changes into a proprietary software product. </p> <p> When we explain to the employer that it is illegal to distribute the improved version except as free software, the employer usually decides to release it as free software rather than throw it away. </p> <p> To copyleft a program, we first state that it is copyrighted; then we add distribution terms, which are a legal instrument that gives everyone the rights to use, modify, and redistribute the program's code <em>or any program derived from it</em> but only if the distribution terms are unchanged. Thus, the code and the freedoms become legally inseparable. </p> <p> Proprietary software developers use copyright to take away the users' freedom; we use copyright to guarantee their freedom. That's why we reverse the name, changing “copyright” into “copyleft”. </p> <p> Copyleft is a general concept; there are many ways to fill in the details. In the GNU Project, the specific distribution terms that we use are contained in the GNU General Public License, the GNU Lesser General Public License and the GNU Free Documentation License. </p> <p> The appropriate license is included in many manuals and in each GNU source code distribution. </p> <p> The GNU GPL is designed so that you can easily apply it to your own program if you are the copyright holder. You don't have to modify the GNU GPL to do this, just add notices to your program which refer properly to the GNU GPL. Please note that you must use the entire text of the GPL, if you use it. It is an integral whole, and partial copies are not permitted. (Likewise for the LGPL, AGPL, and FDL.) </p> <p> Using the same distribution terms for many different programs makes it easy to copy code between various different programs. Since they all have the same distribution terms, there is no need to think about whether the terms are compatible. The Lesser GPL includes a provision that lets you alter the distribution terms to the ordinary GPL, so that you can copy code into another program covered by the GPL. </p> <h3 id="OtherWorks">Licenses for Other Types of Works</h3> <p> We believe that published software and documentation should be <a href="/philosophy/free-doc.html">free software and free documentation</a>. We recommend making all sorts of educational and reference works free also, using free documentation licenses such as the <a href="#FDL">GNU Free Documentation License</a> (GNU FDL). </p> <p>For essays of opinion and scientific papers, we recommend either the <ahref="http://creativecommons.org/licenses/by-nd/3.0/us/">Creativehref="https://creativecommons.org/licenses/by-nd/3.0/us/">Creative Commons Attribution-NoDerivs 3.0 United States License</a>, or the simple “verbatim copying only” license stated above.</p> <p> We don't take the position that artistic or entertainment works must be free, but if you want to make one free, we recommend the <a href="//directory.fsf.org/wiki/License:Free-Art-L-v1.3">Free Art License</a>.</p> </div> </div><!-- for id="content", starts in the include above --> <!--#include virtual="/server/footer.html" --> <div id="footer" role="contentinfo"> <div class="unprintable"> <p>Please send general FSF & GNU inquiries to <a href="mailto:gnu@gnu.org"><gnu@gnu.org></a>. There are also <a href="/contact/">other ways to contact</a> the FSF. Broken links and other corrections or suggestions can be sent to <a href="mailto:webmasters@gnu.org"><webmasters@gnu.org></a>.</p> <p><!-- TRANSLATORS: Ignore the original text in this paragraph, replace it with the translation of these two: We work hard and do our best to provide accurate, good quality translations. However, we are not exempt from imperfection. Please send your comments and general suggestions in this regard to <a href="mailto:web-translators@gnu.org"> <web-translators@gnu.org></a>.</p> <p>For information on coordinating and contributing translations of our web pages, see <a href="/server/standards/README.translations.html">Translations README</a>. --> Please see the <a href="/server/standards/README.translations.html">Translations README</a> for information on coordinating and contributing translations of this article.</p> </div> <!-- Regarding copyright, in general, standalone pages (as opposed to files generated as part of manuals) on the GNU web server should be under CC BY-ND 4.0. Please do NOT change or remove this without talking with the webmasters or licensing team first. Please make sure the copyright date is consistent with the document. For web pages, it is ok to list just the latest year the document was modified, or published. If you wish to list earlier years, that is ok too. Either "2001, 2002, 2003" or "2001-2003" are ok for specifying years, as long as each year in the range is in fact a copyrightable year, i.e., a year in which the document was published (including being publicly visible on the web or in a revision control system). There is more detail about copyright years in the GNU Maintainers Information document, www.gnu.org/prep/maintain. --> <p>Copyright © 2014, 2015, 2016, 2018, 2020,20212021, 2022 Free Software Foundation, Inc.</p> <p>This page is licensed under a <a rel="license" href="http://creativecommons.org/licenses/by-nd/4.0/">Creative Commons Attribution-NoDerivatives 4.0 International License</a>.</p> <!--#include virtual="/server/bottom-notes.html" --> <p class="unprintable">Updated: <!-- timestamp start --> $Date: 2022/04/12 10:05:58 $ <!-- timestamp end --> </p> </div> </div><!-- for class="inner", starts in the banner include --> </body> </html>