Comparison of free and open-source software licences
This is a comparison of free and open-source software licences. The comparison only covers software licences 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 licences not specifically intended for software, see List of free content licences.
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 licences. The Open Source Initiative (OSI) is one such organization keeping a list of open-source licences. The Free Software Foundation (FSF) maintains a list of what it considers free. FSF's free software and OSI's open-source licences together are called FOSS licences. There are licences accepted by the OSI which are not free as per the free software definition. The open source definition allows for further restrictions like price, type of contribution and origin of the contribution, e.g. the case of the NASA Open Source Agreement, which requires the code to be "original" work. The OSI does not endorse FSF licence analysis (interpretation) as per their disclaimer.
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 licences, like the Apache License, and all Free Software licences allow commercial use of FOSS components.
This article may be confusing or unclear to readers. In particular, values used in the below table are not defined and some are ambiguous. (May 2020) (Learn how and when to remove this template message)
For a simpler comparison across the most common licenses see free-software license comparison.
The following table compares various features of each licence and is a general guide to the terms and conditions of each licence, based on seven subjects or categories. Recent tools like the European Commissions' Joinup Licensing Assistant, makes possible the licenses selection and comparison based on more than 40 subjects or categories, with access to their SPDX identifier and full text. The table below lists the permissions and limitations regarding the following subjects:
- Linking - linking of the licensed code with code licensed under a different licence (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 licence (for example a copyright) or must retain the same licence under which it was provided
- TM grant - use of trademarks associated with the licensed code or its contributors by a licensee
|Licence||Author||Latest version||Publication date||Linking||Distribution||Modification||Patent grant||Private use||Sublicensing||TM grant|
|Academic Free License||Lawrence E. Rosen||3.0||2002||Permissive||Permissive||Permissive||Yes||Yes||Permissive||No|
|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||With restrictions||No||Permissive||With restrictions||No|
|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|
|CC BY||Creative Commons||4.0||2002||Permissive||Permissive||Permissive||No||Yes||Permissive||No|
|CC BY-SA||Creative Commons||4.0||2002||Copylefted||Copylefted||Copylefted||No||Yes||Copylefted||No|
|CeCILL||CEA / CNRS / INRIA||2.1||June 21, 2013||Permissive||Permissive||Permissive||No||Permissive||With restrictions||No|
|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||N/A||1995||Permissive||Permissive||Permissive||Manually||Yes||?||Manually|
|Eclipse Public License||Eclipse Foundation||2.0||August 24, 2017||Limited||Limited||Limited||Yes||Yes||Limited||Manually|
|Educational Community License||Indiana University||1.0||2007||Permissive||?||Permissive||?||?||?||?|
|European Union Public Licence||European Commission||1.2||May 2017||Permissive, according to EU law (Recitals 10 & 15 Directive 2009/24/EC)||Copylefted, with an explicit compatibility list||Copylefted, with an explicit compatibility list||Yes||Yes||Copylefted, with an explicit compatibility list||No|
|FreeBSD||The FreeBSD project||N/A||April 1999||Permissive||Permissive||Permissive||Manually||Permissive||Permissive||Manually|
|GNU Affero General Public License||Free Software Foundation||3.0||2007||GNU GPLv3 only||Copylefted||Copylefted||Yes||No network usage||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||?||?||?||?|
|ISC license||Internet Systems Consortium||N/A||June 2003||Permissive||Permissive||Permissive||Manually||Permissive||Permissive||Manually|
|LaTeX Project Public License||LaTeX project||1.3c||?||Permissive||?||Permissive||?||?||?||?|
|Microsoft Public License||Microsoft||N/A||?||Copylefted||Copylefted||Copylefted||No||Permissive||?||No|
|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||Copylefted||Yes||Yes||Copylefted||?|
|OpenSSL license||OpenSSL Project||N/A||?||Permissive||?||Permissive||?||?||?||?|
|PHP License||PHP Group||3.01||2019||With restrictions||With restrictions||With restrictions||Yes||Yes||With restrictions||Manually|
|Python Software Foundation License||Python Software Foundation||3.9.1||2020-10-05||Permissive||Permissive||Permissive||Yes||Permissive||Permissive||No|
|Q Public License||Trolltech||?||?||Limited||?||Limited||?||?||?||?|
|Sleepycat License||Sleepycat Software||N/A||1996||Permissive||With restrictions||Permissive||No||Yes||No||No|
|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)||Banlu Kemiyatorn, Sam Hocevar||2||December 2004||Permissive/Public domain||Permissive/Public domain||Permissive/Public domain||No||Yes||Yes||No|
|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||?||?||?||?|
Other licences that don't have information:
|Licence||Author||Latest version||Publication date|
|Eiffel Forum License||NICE||2||2002|
|Intel Open Source License||Intel Corporation||N/A||?|
|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|
|Zope Public License||Zope Foundation||2.1||?|
This table lists for each licence what organizations from the FOSS community have approved it – be it as a "free software" or as an "open source" licence – , how those organizations categorize it, and the licence compatibility between them for a combined or mixed derivative work. Organizations usually approve specific versions of software licences. For instance, a FSF approval means that the Free Software Foundation (FSF) considers a licence to be free software licence. The FSF recommends at least "Compatible with GPL" and preferably copyleft. The OSI recommends a mix of permissive and copyleft licences, 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 licence. 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". Free Software Foundation. Retrieved August 8, 2011.
- "Various Licenses and Comments about Them: NASA Open Source Agreement". Free Software Foundation.
- "Licenses by Name". Open Source Initiative.
- "Other Resources & Disclaimer". Open Source Initiative.
While the OSI acknowledges these as potentially helpful resources for the community, it does not endorse any content, contributors or license interpretations from these websites.[...]The OSI does not promote or exclusively favor any of the above resources, but instead mentions them as a neutral, separate third-party.
- "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.
- "Joinup Licensing Assistant". Retrieved 31 March 2020.
- "OSL 3.0 Explained".
- "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)
- "Compatible Licenses". Creative Commons.
- "the eclipse public license version 1".
- Greenstein, Daniel; Wheeler, Brad (1 March 2007). "Open Source Collaboration in Higher Education: Guidelines and Report of the Licensing and Policy Framework Summit for Software Sharing in Higher Education" – via scholarworks.iu.edu.
- "EUPL compatible open source licences".
- "EUPL text (1.1 & 1.2)".
- "FreeBSD license".
- : 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".
- "PHP Licence 3.01".
- 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.
- 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.
- "Various Licenses and Comments about Them". Free Software Foundation. 2016-01-05. Retrieved 2016-01-05.
- "Licensing/Beerware". Fedora Project. Retrieved 2015-03-10.
- "3-clause BSD License at OSI".
- "[License-review] Please rename "Free Public License-1.0.0" to 0BSD". Open Source Initiative. Retrieved 2019-02-11.
- "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.CS1 maint: uses authors parameter (link)
- Dustin Kirkland (18 February 2016). "ZFS Licensing and Linux". Ubuntu Insights. Canonical.CS1 maint: uses authors parameter (link)
- 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
- "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".
- "[License-review] Request for legacy approval: The Unlicense".
- "OSI Board Meeting Minutes, Wednesday, March 4, 2009".
- Free Software Foundation. "XFree86 1.1 License". Licenses. Free Software Foundation.