Editing Apache License

{{Short description|Free software license}}
{{Use dmy dates|date=January 2015}}
{{Use American English|date=March 2021}}
{{Infobox software license
| name = Apache License
| image = ASF Logo.svg
| caption = The Apache Software Foundation logo
| author = [[The Apache Software Foundation]]
| version = 2.0
| copyright = The Apache Software Foundation
| date = {{Start date and age|2004|01}}
| spdx = Apache-2.0<br />Apache-1.1<br />Apache-1.0
| OSI approved = Yes<ref name="osi">{{cite web
 | title = OSI-approved licenses by name David Gutierrez & David Louie Gutierrez
 | url = http://www.opensource.org/licenses/alphabetical
 | publisher = [[Open Source Initiative]]
 | access-date = 31 March 2011
 | archive-url = https://web.archive.org/web/20110428141712/http://opensource.org/licenses/alphabetical| archive-date= 28 April 2011 | url-status= live}}</ref>
| Debian approved = Yes<ref name="dfsglist">{{cite web
 |url=https://wiki.debian.org/DFSGLicenses#The_Apache_Software_License_.28ASL.29
 |title=The Apache Software License (ASL)
 |work=The Big DFSG-compatible Licenses
 |publisher=[[Debian Project]]
 |access-date=6 July 2009
}}</ref>
| FSF approved = Yes<ref name="fsflist">{{cite web
 |url=https://www.gnu.org/licenses/license-list.html#apache2
 |title=Apache License, Version 2.0
 |work=Various Licenses and Comments about Them
 |publisher=[[Free Software Foundation]]
 |access-date=6 July 2009
 |archive-url=https://web.archive.org/web/20090716201618/https://www.gnu.org/licenses/license-list.html| archive-date= 16 July 2009 | url-status= live}}</ref>
| GPL compatible = Only version 2.0 is compatible with only [[GNU General Public License#Version 3|GPLv3]].<ref name="fsflist" />
| copyleft = No <!-- see [[Copyleft]] -->
| linking = Yes
| website = {{URL|https://www.apache.org/licenses}}
}}

The '''Apache License''' is a [[Permissive free software license|permissive]] free software license written by the [[Apache Software Foundation]] (ASF).<ref name="nmr-permissive">{{cite web|url=http://www.newmediarights.org/open_source/new_media_rights_open_source_licensing_guide |title=Open Source Licensing Guide |author=New Media Rights |publisher=[[California Western School of Law]] |date=2008-09-12|access-date=2015-11-28 |quote=''The 'BSD-like' licenses such as the BSD, MIT, and Apache licenses are extremely permissive, requiring little more than attributing the original portions of the licensed code to the original developers in your own code and/or documentation.''}}</ref> It allows users to use the software for any purpose, to distribute it, to modify it, and to distribute modified versions of the software under the terms of the license, without concern for [[royalties]]. The ASF and its projects release their software products under the Apache License. The license is also used by many non-ASF projects.

==History==
Beginning in 1995, the Apache Group (later the Apache Software Foundation) released successive versions of the [[Apache HTTP Server]]. Its initial license was essentially the same as the [[Original BSD license|original 4-clause BSD license]], with only the names of the organizations changed, and with an additional clause forbidding derivative works from bearing the Apache name.

In July 1999, the [[Berkeley Software Distribution]] accepted the argument put to it by the [[Free Software Foundation]] and retired their ''advertising clause'' (clause 3) to form the new 3-clause BSD license. In 2000, Apache did likewise and created the Apache License 1.1, in which derived products are no longer required to include attribution in their advertising materials, only in their documentation. Individual packages licensed under the 1.1 version may have used different wording due to varying requirements for attribution or mark identification, but the binding terms were the same.

In January 2004, ASF decided to depart from the BSD model and produced the Apache License 2.0. The stated goals of the license included making it easier for non-ASF projects to use, improving [[License compatibility|compatibility]] with [[GNU General Public License|GPL]]-based software, allowing the license to be included by reference instead of listed in every file, clarifying the license on contributions, and requiring a patent license on contributions that necessarily infringe a contributor's own patents.<ref name="Apache licenses">{{cite web|url=https://www.apache.org/licenses/LICENSE-2.0|title=Apache License, Version 2.0|access-date=15 July 2019| publisher= Apache Software Foundation }}</ref> This license requires the preservation of the [[copyright]] notice and [[disclaimer]].

==Licensing conditions==
The Apache License is [[Permissive free software license|permissive]]; unlike [[copyleft]] licenses, it does not require a [[derivative work]] of the software, or modifications to the original, to be distributed using the same license. It still requires application of the same license to all unmodified parts. In every licensed file, original copyright, patent, trademark, and attribution notices must be preserved (excluding notices that do not pertain to any part of the derivative works). In every licensed file changed, a notification must be added stating that changes have been made to that file.

If a <code>NOTICE</code> text file is included as part of the distribution of the original work, then derivative works must include a readable copy of these notices within a <code>NOTICE</code> text file distributed as part of the derivative works, within the source form or documentation, or within a display generated by the derivative works (wherever such third-party notices normally appear).

The contents of the <code>NOTICE</code> file do not modify the license, as they are for informational purposes only, and adding more attribution notices as addenda to the <code>NOTICE</code> text is permissible, provided that these notices cannot be understood as modifying the license. Modifications may have appropriate copyright notices, and may provide different license terms for the modifications.

Unless explicitly stated otherwise, any contributions submitted by a licensee to a licensor will be under the terms of the license without any terms and conditions, but this does not preclude any separate agreements with the licensor regarding these contributions.

=== Apache License 2.0 ===
The Apache License 2.0 attempts to forestall potential patent litigation in Section 3. The user is granted a patent license from each contributor to "make, have made, use, offer to sell, sell, import, and otherwise transfer the Work." Through an ''[[in terrorem]]'' clause, if the user sues anyone alleging that the software or a contribution within it constitutes patent infringement, any such patent licenses for that work are terminated.

==Compatibility==
The Apache Software Foundation and the [[Free Software Foundation]] agree that the Apache License 2.0 is a [[free software license]], compatible with the [[GNU General Public License]]<ref name="Apache licenses" /> (GPL) version 3,<ref name="fsflist"/> meaning that code under [[GNU General Public License#Version 3|GPLv3]] and Apache License 2.0 can be combined, as long as the resulting software is licensed under the GPLv3.<ref>{{cite web|url=http://www.apache.org/licenses/GPL-compatibility.html|title=Apache License v2.0 and GPL Compatibility|author=Apache Software Foundation|access-date=30 January 2008| archive-url= https://web.archive.org/web/20080115045635/http://www.apache.org/licenses/GPL-compatibility.html| archive-date= 15 January 2008 | url-status= live}}</ref>

The Free Software Foundation considers all versions of the Apache License to be [[License compatibility|incompatible]] with the previous GPL versions 1 and 2.<ref name="fsflist"/> Furthermore, it considers Apache License versions before 2.0 incompatible with GPLv3. Because of version 2.0's patent license requirements, the Free Software Foundation recommends it over other non-copyleft licenses.<ref>{{cite web|url=https://gnu.org/licenses/license-recommendations.html|title=How to choose a license for your own work|date=15 December 2018|website=gnu.org|publisher=[[Free Software Foundation]]|access-date=25 August 2019}}</ref><ref name="fsflist"/> If the Apache License with the LLVM exception is used, then it is compatible with GPLv2.<ref>{{Cite web |title=LLVM Exception {{!}} Software Package Data Exchange (SPDX) |url=https://spdx.org/licenses/LLVM-exception.html |access-date=2022-06-22 |website=spdx.org}}</ref>

==Reception and adoption==
In October 2012, 8,708 projects located at [[SourceForge.net]] were available under the terms of the Apache License.<ref>{{cite web|url=http://sourceforge.net/search/?&fq%5B%5D=trove%3A401|title=Projects at SourceForge under Apache License|access-date=28 October 2012}}</ref>  In a blog post from May 2008, [[Google]] mentioned that over 25% of the nearly 100,000 projects then hosted on [[Google Code]] were using the Apache License,<ref>{{cite web|url=http://google-opensource.blogspot.com/2008/05/standing-against-license-proliferation.html|title=Standing Against License Proliferation|last=Stein|first=Greg|date=28 May 2008|website=Google Open Source Blog}}</ref> including the [[Android (operating system)|Android operating system]].<ref>{{Cite web|url=https://source.android.com/setup/start/licenses|title=Licenses|website=Android Open Source Project|access-date=2019-08-25}}</ref>

{{As of|2015}}, according to [[Black Duck Software]]<ref name="blackduck2015">{{cite web|url=http://www.blackducksoftware.com/resources/data/top-20-licenses|title=Top 20 licenses|date=19 November 2015|publisher=Black Duck Software|archive-url=https://web.archive.org/web/20160719043600/https://www.blackducksoftware.com/top-open-source-licenses|archive-date=19 July 2016|url-status=dead|access-date=19 November 2015}}</ref> and [[GitHub]],<ref name="github">{{cite web|url=https://github.com/blog/1964-license-usage-on-github-com|title=Open source license usage on GitHub.com|last=Balter|first=Ben|date=9 March 2015|website=[[GitHub]]}}</ref> the Apache license is the third most popular license in the [[FOSS]] domain after [[MIT License]] and [[GPLv2]].

The [[OpenBSD]] project does not consider the Apache License 2.0 to be an acceptable free license because of its patent provisions. The OpenBSD policy believes that when the license forces one to give up a legal right that one otherwise has, that license is no longer free. Moreover, the project objects to involving [[contract law]] with copyright law, stating "...Copyright law is somewhat standardized by international agreements, contract law differs wildly among jurisdictions. So what the license means in different jurisdictions may vary and is hard to predict."<ref>{{cite web|url=http://www.openbsd.org/policy.html|title=OpenBSD copyright policy|date=28 May 2019|website=openbsd.org|publisher=OpenBSD Project}}</ref>

==See also==
{{Portal|Free and open-source software}}
*[[Comparison of free and open-source software licenses]]
*[[List of Apache Software Foundation projects]]
*[[:Category:Software using the Apache license|Software using the Apache license (category)]]

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

==External links==
* {{Official website|https://www.apache.org/licenses|Apache Licenses}}
* [https://www.tldrlegal.com/license/apache-license-2-0-apache-2-0 Quick Summary of the Apache License 2.0]

{{Apache Software Foundation}}
{{FOSS}}

[[Category:Apache Software Foundation|License]]
[[Category:Free and open-source software licenses]]
[[Category:Permissive software licenses]]
[[Category:Software using the Apache license]]