Comparison of free and open-source software licenses
This comparison only covers software licenses which have a linked Wikipedia article for details and which are approved by at least one of the following expert groups: the Free Software Foundation, the Open Source Initiative, the Debian Project and the Fedora Project. For a list of licenses not specifically intended for software, see List of free-content licences.
FOSS 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 (OSI) is one such organization keeping a list of open-source licenses. The Free Software Foundation (FSF) maintains a list of what it considers free. FSF's free software and OSI's open-source licenses together are called FOSS licenses. There are licenses 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 license 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 licenses, like the Apache License, and all Free Software licenses allow commercial use of FOSS components.
General comparison
For a simpler comparison across the most common licenses see free-software license comparison.
The following table compares various features of each license and is a general guide to the terms and conditions of each license, 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 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
- TM grant - use of trademarks associated with the licensed code or its contributors by a licensee
In this table, "permissive" means the software has minimal restrictions on how it can be used, modified, and redistributed, usually including a warranty disclaimer. "Copyleft" means the software requires that its source code be made publicly available and that all provisions in the license be preserved in derivative works.
| License | 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 |
| Beerware | Poul-Henning Kamp | 42 | 1987 | Permissive | Permissive | Permissive | No | Permissive | Permissive | 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 | — | 1995 | Permissive | Permissive | Permissive | Manually | Yes | ? | Manually |
| Eclipse Public License | Eclipse Foundation | 2.0 | August 24, 2017 | Permissive | Copylefted | Copylefted | Yes | Yes | Copylefted | No |
| 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 | — | 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 | — | June 2003 | Permissive | Permissive | Permissive | Manually | Permissive | Permissive | Manually |
| LaTeX Project Public License | LaTeX project | 1.3c | ? | Permissive | ? | Permissive | ? | ? | ? | ? |
| Microsoft Public License | Microsoft | — | ? | Copylefted | Copylefted | Copylefted | No | Permissive | ? | No |
| MIT license / X11 license | MIT | — | 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 | — | ? | 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 | May 10, 2020 | Permissive | Permissive | Permissive | Yes | Permissive | Permissive | No |
| Q Public License | Trolltech | ? | ? | Limited | ? | Limited | ? | ? | ? | ? |
| Sleepycat License | Sleepycat Software | — | 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" |
XMOS | ? | February 2011 | Permissive | Permissive | Permissive | Manually | Yes | Permissive | ? |
| XFree86 1.1 License | The XFree86 Project, Inc | ? | ? | Permissive | ? | Permissive | ? | ? | ? | ? |
| zlib/libpng license | Jean-Loup Gailly and Mark Adler | ? | ? | Permissive | ? | Permissive | ? | ? | ? | ? |
Other licenses that don't have information:
| license | Author | Latest version | Publication date |
|---|---|---|---|
| Eiffel Forum License | NICE | 2 | 2002 |
| Intel Open Source License | Intel Corporation | — | ? |
| 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 | — | 2003-01-28 |
| Zope Public License | Zope Foundation | 2.1 | ? |
| Server Side Public License | MongoDB | 1.0 | 2018-10-16 |
Approvals
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.