Comparison of free and open-source software licenses
This is a comparison of published free software licenses and open-source licenses. The comparison only covers software licenses with a linked article for details, approved by at least one expert group at the FSF, the OSI, the Debian project, or the Fedora project. For a list of licenses not specifically intended for software, see List of free content licenses.
FOSS stands for "Free and Open Source Software". There is no one universally agreed-upon definition of FOSS software and various groups maintain approved lists of licenses. The Open Source Initiative is one such organization keeping a list of open-source licenses. The Free Software Foundation maintains a list of what it considers free. FSF's free software and OSI's open-source licenses together are called FOSS licenses. Due to some seldom conflicting cornercases technically not synonymous, for all practical considerations they are identical and widely used interchangeably.
The FSF's Free Software definition focuses on the user's unrestricted rights to use a program, to study and modify it, to copy it, and redistribute it for any purpose, which are considered by the FSF the four essential freedoms. The OSI's open-source criteria focuses on the availability of the source code and the advantages of an unrestricted and community driven development model. Yet, many FOSS licenses, like the Apache license, and all Free Software licenses allow commercial use of FOSS components.
The following table compares various features of each license and is a general guide to the terms and conditions of each license. The table lists the permissions and limitations regarding the following subjects:
- Linking - linking of the licensed code with code licensed under a different license (e.g. when the code is provided as a library)
- Distribution - distribution of the code to third parties
- Modification - modification of the code by a licensee
- Patent grant - protection of licensees from patent claims made by code contributors regarding their contribution, and protection of contributors from patent claims made by licensees
- Private use - whether modification to the code must be shared with the community or may be used privately (e.g. internal use by a corporation)
- Sublicensing - whether modified code may be licensed under a different license (for example a copyright) or must retain the same license under which it was provided
- Trademark grant - use of trademarks associated with the licensed code or its contributors by a licensee
|License||Author||Latest version||Publication date||Linking||Distribution||Modification||Patent grant||Private use||Sublicensing||TM grant|
|Academic Free License||Lawrence E. Rosen||3||2002||Permissive||?||Permissive||?||?||?||?|
|Affero General Public License||Affero Inc||2.0||2007||Copylefted||Copyleft except for the GNU AGPL||Copyleft||?||Yes||?||?|
|Apache License||Apache Software Foundation||2.0||2004||Permissive||Permissive||Permissive||Yes||Yes||Permissive||No|
|Apple Public Source License||Apple Computer||2.0||August 6, 2003||Permissive||?||Limited||?||?||?||?|
|Artistic License||Larry Wall||2.0||2000||With restrictions||?||With restrictions||?||?||?||?|
|Berkeley Database License||Oracle Corporation||?||February 7, 2008||?||?||?||?||?||?||?|
|BSD License||Regents of the University of California||3.0||?||Permissive||Permissive||Permissive||Manually||Yes||Permissive||Manually|
|Boost Software License||?||1.0||August 17, 2003||Permissive||?||Permissive||?||?||?||?|
|Creative Commons Zero||Creative Commons||1.0||2009||Public Domain||Public Domain||Public Domain||No||Public Domain||Public Domain||No|
|CeCILL||CEA / CNRS / INRIA||2.0||May 21, 2005||?||?||?||?||?||?||?|
|Common Development and Distribution License||Sun Microsystems||1.0||December 1, 2004||Permissive||?||Limited||?||?||?||?|
|Common Public License||IBM||1.0||May 2001||Permissive||?||Copylefted||?||?||?||?|
|Cryptix General License||Cryptix Foundation||?||1995||Permissive||Permissive||Permissive||Manually||Yes||?||Manually|
|Eclipse Public License||Eclipse Foundation||1.0||February 2004||Limited||Limited||Limited||Yes||Yes||Limited||Manually|
|Educational Community License||?||1.0||?||Permissive||?||Permissive||?||?||?||?|
|Eiffel Forum License||NICE||2||2002||?||?||?||?||?||?||?|
|EUPL||European Commission||1.1||January 2009||Limited||?||With an explicit compatibility list||?||?||?||?|
|GNU Affero General Public License||Free Software Foundation||3.0||2007||GNU GPLv3 only||Copylefted||Copylefted||Yes||Copylefted||Copylefted||Yes|
|GNU General Public License||Free Software Foundation||3.0||June 2007||GPLv3 compatible only||Copylefted||Copylefted||Yes||Yes||Copylefted||Yes|
|GNU Lesser General Public License||Free Software Foundation||3.0||June 2007||With restrictions||Copylefted||Copylefted||Yes||Yes||Copylefted||Yes|
|IBM Public License||IBM||1.0||August 1999||Copylefted||?||Copylefted||?||?||?||?|
|Intel Open Source License||Intel Corporation||?||?||?||?||?||?||?||?||?|
|ISC license||Internet Systems Consortium||?||June 2003||Permissive||Permissive||Permissive||?||?||?||?|
|LaTeX Project Public License||LaTeX project||1.3c||?||Permissive||?||Permissive||?||?||?||?|
|MIT license / X11 license||MIT||N/A||1988||Permissive||Permissive||Permissive||Manually||Yes||Permissive||Manually|
|Mozilla Public License||Mozilla Foundation||2.0||January 3, 2012||Permissive||Copylefted||Copylefted||Yes||Yes||Copylefted||No|
|Netscape Public License||Netscape||1.1||?||Limited||?||Limited||?||?||?||?|
|Open Software License||Lawrence Rosen||3.0||2005||Permissive||?||Copylefted||?||?||?||?|
|OpenSSL license||OpenSSL Project||?||?||Permissive||?||Permissive||?||?||?||?|
|PHP License||PHP Group||3.01||?||?||?||?||?||?||?||?|
|Python Software Foundation License||Python Software Foundation||2||?||Permissive||?||Permissive||?||?||?||?|
|Q Public License||Trolltech||?||?||Limited||?||Limited||?||?||?||?|
|RealNetworks Public Source License||RealNetworks||?||?||?||?||?||?||?||?||?|
|Reciprocal Public License||Scott Shattuck||1.5||2007||?||?||?||?||?||?||?|
|Sun Industry Standards Source License||Sun Microsystems||?||?||?||?||?||?||?||?||?|
|Sun Public License||Sun Microsystems||?||?||?||?||?||?||?||?||?|
|Sybase Open Watcom Public License||Open Watcom||N/A||2003-01-28||?||?||?||?||?||?||?|
|Unlicense||unlicense.org||1||December 2010||Permissive/Public domain||Permissive/Public domain||Permissive/Public domain||?||Permissive/Public domain||Permissive/Public domain||?|
|W3C Software Notice and License||W3C||20021231||December 31, 2002||Permissive||?||Permissive||?||?||?||?|
|Do What The Fuck You Want To Public License (WTFPL)||Sam Hocevar||2||December 2004||Permissive/Public domain||?||Permissive/Public domain||?||?||?||?|
|XCore Open Source License
also separate "Hardware License Agreement"
|XFree86 1.1 License||The XFree86 Project, Inc||?||?||Permissive||?||Permissive||?||?||?||?|
|zlib/libpng license||Jean-Loup Gailly and Mark Adler||?||?||Permissive||?||Permissive||?||?||?||?|
|Zope Public License||Zope Foundation||2.1||?||?||?||?||?||?||?||?|
This table lists for each license what organizations from the FOSS community have approved it – be it as a "free software" or as an "open source" license – , how those organizations categorize it, and the license compatibility between them for a combined or mixed derivative work. Organizations usually approve specific versions of software licenses. For instance, a FSF approval means that the Free Software Foundation (FSF) considers a license to be free software license. The FSF recommends at least "Compatible with GPL" and preferably copyleft. The OSI recommends a mix of permissive and copyleft licenses, the Apache License 2.0, 2- & 3-clause BSD license, GPL, LGPL, MIT license, MPL 2.0, CDDL and EPL.
- The original version of the Artistic License is defined as non-free because it is overly vague, not because of the substance of the license. The FSF encourages projects to use the Clarified Artistic License instead.
- But can be made compatible by upgrading to GPLv3 via the optional "or later" clause added in most GPLv2 license texts.
- But not with GPLv2 without "or later" clause.
- MPL 2.0 is GPL compatible unless marked "Incompatible with Secondary Licenses".
- Listed as WTFPL.
- Open source licenses - Licenses by Name on opensource.org
- "Various Licenses and Comments about Them". Retrieved August 8, 2011.
- What is "free software" and is it the same as "open source"? on opensource.com "The FSF uses a shorter, four-point definition of software freedom when evaluating licenses, while the OSI uses a longer, ten-point definition. The two definitions lead to the same result in practice, but use superficially different language to get there."
- "Relationship between the Free Software movement and Open Source movement", Free Software Foundation, Inc
- "What is Free Software", Free Software Foundation, Inc
- opensource.org/about "Open source is a development method for software that harnesses the power of distributed peer review and transparency of process. The promise of open source is better quality, higher reliability, more flexibility, lower cost, and an end to predatory vendor lock-in."
- Popp, Dr. Karl Michael (2015). Best Practices for commercial use of open source software. Norderstedt, Germany: Books on Demand. ISBN 978-3738619096.
- "affero.org: Affero General Public License version 2 (AGPLv2)".
- "the section 4 of the apache license version 2".
- "BSD license".
- "Using CC0 for public domain software". Creative Commons. April 15, 2011. Retrieved May 10, 2011.
- "Various Licenses and Comments about Them". GNU Project. Retrieved April 4, 2015.
- cc-by-4-0-and-cc-by-sa-4-0-added-to-our-list-of-free-licenses (2015)
- "the eclipse public license version 1".
- : section 13 of the GNU AGPLv3 license
- : GNU licenses copyleft
- "the GNU Affero General Public License version 3".
- : If library is under GPLv3
- "the GNU General Public License version 3".
- : the section 4 of the GNU Lesser General Public License version 3
- "the GNU Lesser General Public License version 3".
- "MIT License".
- "MPL version 2".
- Free Software Foundation. "Various Licenses and Comments about Them". Licenses. Free Software Foundation.
- Free Software Foundation. "To be GPL-Compatible has to be compatible with Licenses GNU GPLv3 and GNU GPLv2 – Free Software Foundation". Software Licenses. Free Software Foundation.
- Free Software Foundation. "GPL-Compatible Free Software Licenses – Free Software Foundation". Software Licenses. Free Software Foundation.
- Free Software Foundation. "GPL-Incompatible Free Software Licenses – Free Software Foundation". Software Licenses. Free Software Foundation.
- Free Software Foundation. "GPL-compatible Definition by FSF – Free Software Foundation". GPL-compatible Definition. Free Software Foundation.
- Free Software Foundation. "GPL-compatible Definition previous version by FSF – Free Software Foundation". GPL-compatible Definition. Free Software Foundation.
- Open Source Initiative. "The Approved Licenses". License Information. Open Source Initiative.
- Copyfree Initiative. "Copyfree Licenses". Copyfree Initiative.
- "Rejected Licenses". CopyFree Initiative. Retrieved June 16, 2013.
- Debian. "Debian – License information". Licenses. Debian.
- "The DFSG and Software Licenses". Debian wiki.
- Fedora. "Licensing – FedoraProject". Licenses. Fedora Project.
- Free Software Foundation. "Apache License, Version 2.0". Licenses. Free Software Foundation.
- "Apple Public Source License (APSL), version 1.x". Retrieved 2013-08-07.
- "Licensing/Beerware". Fedora Project. Retrieved 2015-03-10.
- "3-clause BSD License at OSI".
- "Various Licenses and Comments About Them - Common Development and Distribution License". Free Software Foundation. Retrieved 2006-12-31.
- Michael Larabel (6 October 2015). "Ubuntu Is Planning To Make The ZFS File-System A "Standard" Offering". Phoronix.
- Dustin Kirkland (18 February 2016). "ZFS Licensing and Linux". Ubuntu Insights. Canonical.
- Are GPLv2 and CDDL incompatible? on hansenpartnership.com by James E.J. Bottomley "What the above analysis shows is that even though we presumed combination of GPLv2 and CDDL works to be a technical violation, there's no way actually to prosecute such a violation because we can’t develop a convincing theory of harm resulting. Because this makes it impossible to take the case to court, effectively it must be concluded that the combination of GPLv2 and CDDL, provided you’re following a GPLv2 compliance regime for all the code, is allowable." (23 February 2016)
- Moglen, Eben; Choudhary, Mishi (26 February 2016). "The Linux Kernel, CDDL and Related Issues".
- GPL Violations Related to Combining ZFS and Linux on sfconservancy.org by Bradley M. Kuhn and Karen M. Sandler (February 25, 2016)
- "Various Licenses and Comments about Them - GNU Project - Free Software Foundation".
- "Frequently Answered Questions". opensource.org.
CC0 was not explicitly rejected, but the License Review Committee was unable to reach consensus that it should be approved
- "Copyfree Licenses".
- "Re: Creative Commons CC0".
- "License information".
- "Creative Commons BY-SA 4.0 declared one-way compatible with GNU GPL version 3 — Free Software Foundation — working together for free software".
- Free Software Foundation. "Educational Community License 2.0". Licenses. Free Software Foundation.
- : "We use only licenses that are compatible with the GNU GPL for GNU software."
- "Frequently Asked Questions about the GNU Licenses – Is GPLv3 compatible with GPLv2?". gnu.org. Retrieved 3 June 2014.
No. Some of the requirements in GPLv3, such as the requirement to provide Installation Information, do not exist in GPLv2. As a result, the licenses are not compatible: if you tried to combine code released under both these licenses, you would violate section 6 of GPLv2. However, if code is released under GPL "version 2 or later," that is compatible with GPLv3 because GPLv3 is one of the options it permits.
- "General Resolution: Why the GNU Free Documentation License is not suitable for Debian main".
- Free Software Foundation. "A Quick Guide to GPLv3". Licenses. Free Software Foundation.
- Mozilla Foundation. "MPL 2.0 FAQ". Licenses. Mozilla Foundation.
- "Various Licenses and Comments about Them - GNU Project - Free Software Foundation".
- "Frequently Answered Questions".
- "OSI Board Meeting Minutes, Wednesday, March 4, 2009".
- Free Software Foundation. "XFree86 1.1 License". Licenses. Free Software Foundation.