The following is a list of software licenses which Free Software Foundation (FSF) has approved as complying with The Free Software Definition. They are thus, according to FSF, free software licenses.
| Name | Versions | Is copyleft? | GPL compatible? | Used by | Notes |
|---|---|---|---|---|---|
| Academic Free License | 3.1, 2.1 | No | No | ||
| Affero General Public License | 1 | Yes | No | Version 3 of the AGPL is compatible with the GPL version 3. | |
| GNU Affero General Public License | 3 | Yes | Yes - GPLv3 | StatusNet | Compatible with GPL version 3 only. |
| Apache License | 1.0, 1.1, 2.0 | No | Yes - GPLv3 | Apache | Versions 1.0 and 1.1 of the Apache License are not GPL compatible |
| Apple Public Source License | 2 | No | No | Apple's Darwin operating system and the XNU kernel. | |
| Arphic Public License | Yes | No | |||
| Artistic License | 2.0 | No | Yes | Perl | According to the FSF only version 2 of the Artistic License is compatible with the GPL |
| Berkeley Database License | Yes | Yes | Berkeley DB | Also known as the Sleepycat Software Product License. | |
| Boost Software License | No | Yes | |||
| CeCILL | 2 | Yes | Yes | GPL compatible since version 2 | |
| Clarified Artistic License | No | Yes | NcFTP | ||
| Common Development and Distribution License | Yes | No | Sun's OpenSolaris | ||
| Common Public License | 1.0 | Yes | No | ||
| Cryptix General License | No | Yes | |||
| EU DataGrid Software License | No | Yes | |||
| Eclipse Public License | 1.0 | Yes | No | Eclipse | |
| eCos license | 2.0 | Yes | Yes | eCos | GPL compatible since version 2. |
| Eiffel Forum License | 2 | No | Yes | GPL compatible since version 2. | |
| Expat License | No | Yes | Expat | Also known as the MIT License | |
| GNU General Public License | 1, 2, 3 | Yes | Yes | GNU, Linux kernel, MySQL | |
| GNU Lesser General Public License | 2, 2.1, 3 | Yes | Yes | glibc and many other libraries, themes and icons | |
| IBM Public License | 1.0 | Yes | No | ||
| Intel Open Source License (OSI) | No | Yes | As published by OSI. | ||
| Interbase Public License | 1.0 | No | |||
| ISC license (Internet Systems Consortium license) | 2 | No | Yes | BIND, OpenBSD | ISC License listed as GPL-compatible by the FSF. |
| Jabber Open Source License | 1.0 | No | This license has been voluntarily retired from OSI. | ||
| LaTeX Project Public License | 1.2, 1.3a | No | No | LaTeX | |
| GNAT Modified General Public License | Yes | GNAT runtime toolkit | |||
| License of Netscape Javascript | Yes | ||||
| Vim | 6.1 and later | Yes | Vim | ||
| zlib License | No | Yes | zlib | Also known as the libpng license. | |
| License of the iMatix Standard Function Library | Yes | ||||
| License of xinetd | Yes | No | xinetd | ||
| Lucent Public License | 1.02 | No | Plan 9 | Also known as the Plan 9 License. | |
| MIT License | No | Yes | X.org | Also known as the X11 License. | |
| Modified BSD license | No | Yes | FreeBSD and OpenBSD | ||
| Mozilla Public License (MPL) | Yes (limited) | No | Mozilla and Mozilla Firefox | ||
| Netizen Open Source License | 1.0 | No | |||
| Netscape Public License | Yes | No | |||
| Nokia Open Source License | No | ||||
| Open Software License | 1.0 | Yes | No | ||
| OpenLDAP License | 2.3, 2.7 | Yes | OpenLDAP | GPL compatible since version 2.7 | |
| OpenSSL license | Yes[1] | No | OpenSSL | ||
| Original BSD license | No | No | NetBSD | ||
| PHP License | 3.0 | No | No | PHP | |
| Phorum License | 2.0 | No | |||
| Public domain | - | No | Yes | SQLite | The public domain isn't truly a license, per se. The definition of what is in the public domain varies from country to country, as is whether or not the author of a work can place his/her work voluntarily in the public domain. If a work is in the public domain, (usually) anyone can use, copy, modify, redistribute, or otherwise exploit the work for any purpose as there is no copyright at all. |
| CC0 | 1.0 | No | Yes | CC0 isn't truly a license, but a recommended way of dedicating software to the public domain.[2] | |
| Python Software Foundation License | 1.6a2, 1.6b1 - 2.0/2.1, 2.0.1/2.1.1 | No | Yes | Python | This license replaces the original Python License which was not GPL compatible[3] |
| Q Public License | 1.0 | No | No | TurboHercules | It was used until Qt 3.0, Qt version 4.x is now GPL (version 2 or 3), and LGPL 2.1 |
| Standard ML of New Jersey Copyright License[4] | No | Yes | |||
| Sun Industry Standards Source License | 1.0 | No | Sun Grid Engine | Sun has voluntarily retired this license. | |
| Sun Public License | No | This license seems now to have been "dropped" by Sun in favor of the new CDDL license, which is also derived from the MPL. | |||
| Condor Public License | No | ||||
| Ruby License | Yes | Ruby | |||
| University of Illinois/NCSA Open Source License | 1.0 | No | Yes | Low Level Virtual Machine | May also have been used by NCSA HTTPd |
| Vita Nuova Liberal Source License | Yes | No | |||
| W3C Software Notice and License | No | Yes | libwww | ||
| X11 License | No | Yes | X.org | This is the FSF's preferred name for the MIT License. | |
| WTFPL | 2 | No | Yes | ||
| XFree86 1.1 License | 1.1 | No | Yes - GPLv3 | XFree86 | This license is GPL 3 compatible. The XFree86 Project contests GPL 2 incompatibility.[5] |
| Zend License | 2.0 | No | No | Parts of PHP | |
| Zope Public License | 1, 2.0 | No | Yes | Zope | GPL compatible since version 2.0 |