The Apache logo
|Author||Apache Software Foundation|
|Publisher||Apache Software Foundation|
|GPL compatible||Yes - GPLv3|
|Linking from code with a different license||Yes|
The Apache License pron.: // is a free software license written by the Apache Software Foundation (ASF). The Apache License requires preservation of the copyright notice and disclaimer. Like any free software license, the Apache License allows the user of the software the freedom 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.
All software produced by the ASF or any of its projects or subjects is licensed according to the terms of the Apache License. Some non-ASF software is also licensed using the Apache License. In October 2012, 8708 projects located at SourceForge.net were available under the terms of the Apache License. In a blog post from May 2008, Google mentioned that 25,000 out of the 100,000 projects then hosted on Google Code were using the Apache License, including the Android operating system.
Version history 
The Apache License 1.0 was the original Apache License which applies only to older versions of Apache packages (such as version 1.2 of the Web server).
The Apache License 1.1 was approved by the ASF in 2000: The primary change from the 1.0 license is in the 'advertising clause' (section 3 of the 1.0 license); derived products are no longer required to include attribution in their advertising materials, but only in their documentation.
The ASF adopted the Apache License 2.0 in January 2004. The stated goals of the license included making the license easier for non-ASF projects to use, improving compatibility with 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.
Licensing conditions 
The Apache License is widely, but not universally, considered permissive in that it does not require a derivative work of the software, or modifications to the original, to be distributed using the same license (unlike copyleft licenses - see comparison). It still requires application of the same license to all unmodified parts and, in every licensed file, any original copyright, patent, trademark, and attribution notices in redistributed code must be preserved (excluding notices that do not pertain to any part of the derivative works); and, in every licensed file changed, a notification must be added stating that changes have been made to that file.
If a NOTICE 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 NOTICE 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 NOTICE file do not modify the license, as they are for informational purposes only, and adding more attribution notices as addenda to the NOTICE 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.
GPL compatibility 
The Apache Software Foundation and the Free Software Foundation both agree that the Apache License 2.0 is a free software license, compatible with version 3 of the GNU General Public License (GPL), meaning that code under GPL version 3 and Apache License 2.0 can be combined so long the resulting software is licensed under the GPL version 3.
The Free Software Foundation considers all versions of the Apache License (as of 2013[update]) to be incompatible with the previous GPL versions 1 and 2 and, furthermore, considers Apache License versions before v2.0 incompatible with GPLv3.
See also 
- "The Apache Software License (ASL)". The Big DFSG-compatible Licenses. Debian Project. Retrieved 6 July 2009.
- "Apache License, Version 2.0". Various Licenses and Comments about Them. Free Software Foundation. Archived from the original on 16 July 2009. Retrieved 6 July 2009.
- "OSI-approved licenses by name". Open Source Initiative. Archived from the original on 28 April 2011. Retrieved 31 March 2011.
- "Projects at SourceForge under Apache License". Retrieved 28 October 2012.
- "Standing Against License Proliferation". Retrieved 24 October 2009.
- Android Open Source licenses
- "Licenses - The Apache Software Foundation". Archived from the original on 1 July 2007. Retrieved 7 July 2007.
- "Various Licenses and Comments about Them". Free Software Foundation. 14 January 2008. Archived from the original on 18 January 2008. Retrieved 30 January 2008.
- Apache Software Foundation. "Apache License v2.0 and GPL Compatibility". Archived from the original on 15 January 2008. Retrieved 30 January 2008.
- Free Software Foundation (2013-02-28). "Licenses". Archived from the original on 2013-03-05.