Open source licenses are widely used in Free Open Source Software (FOSS). Some licenses are by far more popular than others and widely used. The main categories mentioned for FOSS licenses refer to permissive, weak copyleft and strong copyleft licenses. However, the licenses approved by the Open Source Initiative (OSI) and the ones approved by the Free Software Foundation (FSF) are not being presented in the respective categories from these organizations. Regarding permissive licenses, a list can be found by the ones approved by the Copyfree initiative.
It is helpful to see in which from these three categories each license corresponds. I present in this post the licenses that have been approved by OSI. Please bear in mind that some licenses possess different properties that do not render them 100% free licenses in order to belong non-ambiguously to the categories of permissive or copyleft. Some licenses have a closer meaning to proprietary licenses without the commercial feature, i.e., they cannot be employed for commercial software. Still, characterizing the license as permissive or not makes sense when it refers to the restrictions imposed on the potential license use.
I am listing in this post the licenses that can be currently found in the OSI-approved license list. Since different procedures are followed by OSI and FSF for a license approval process, not all licenses exist in both organizations. Note that the license list in OSI fratures also a license that has been deprecated by its owner: Historical Permission Notice and Disclaimer (HPND). Any comments are welcome.
| Permissive | Weak copyleft | Strong copyleft | Uncategorized |
Apache License v. 2.0 Boost Software License (BSL-1.0) BSD 3-Clause "New" or "Revised" BSD 3-Clause "Simplified" or "FreeBSD" MIT license (MIT) Academic Free License ("AFL") v. 3.0 Attribution Assurance Licenses (AAL) EU DataGrid Software License (EUDatagrid) Educational Community License, Version 2.0 (ECL-2.0) Eiffel Forum License V2.0 (EFL-2.0) Entessa Public License Version. 1.0 Fair License ISC License (ISC) Lucent Public License Version 1.02 MirOS Licence MIT license (MIT) Multics License Naumen Public License (Naumen) NTP License (NTP) Open Group Test Suite License (OGTSL) PHP License 3.0 (PHP-3.0) PostgreSQL License (PostgreSQL) Python License (Python-2.0) CNRI Python license (CNRI-Python) University of Illinois/NCSA Open Source License (NCSA) Vovida Software License v. 1.0 (VSL-1.0) W3C License (W3C) X.Net License (Xnet) Zope Public License 2.0 (ZPL-2.0) zlib/libpng license (Zlib) | Adaptive Public License v. 1.0 Apple Public Source License (APSL-2.0) Artistic license v. 2.0 Common Development and Distribution License 1.0 (CDDL-1.0) Computer Associates Trusted Open Source License 1.1 (CATOSL-1.1) CUA Office Public License Version 1.0 (CUA-OPL-1.0) Eclipse Public License 1.0 (EPL-1.0) GNU Library or "Lesser" General Public License version 2.1 (LGPL-2.1) GNU Library or "Lesser" General Public License version 3.0 (LGPL-3.0) Microsoft Public License (Ms-PL) Microsoft Reciprocal License (Ms-RL) Motosoto License (Motosoto) Mozilla Public License 2.0 (MPL-2.0) NASA Open Source Agreement 1.3 (NASA 1.3) Nokia Open Source License (Nokia) Ricoh Source Code Public License (RSCPL) Sun Public License 1.0 (SPL-1.0) Sybase Open Watcom Public License 1.0 (Watcom-1.0) wxWindows Library License (WXwindows) |
CeCILL License 2.1 (CECILL-2.1) Common Public Attribution License 1.0 (CPAL-1.0) European Union Public License, Version 1.1 (EUPL-1.1) Frameworx License (Frameworx-1.0) GNU Affero General Public License v3 (AGPL-3.0) GNU General Public License version 2.0 (GPL-2.0) GNU General Public License version 3.0 (GPL-3.0) IBM Public License 1.0 (IPL-1.0) IPA Font License (IPA) Nethack General Public License (NGPL) Non-Profit Open Software License version 3.0 (NPOSL-3.0) Open Font License 1.1 (OFL 1.1) Open Software License 3.0 (OSL-3.0) Reciprocal Public License 1.5 (RPL-1.5) Simple Public License 2.0 (SimPL-2.0) Sleepycat License (Sleepycat) |
LaTeX Project Public License 1.3c (LPPL-1.3c) OCLC Research Public License 2.0 (OCLC-2.0) Q Public License (QPL-1.0) RealNetworks Public Source License V1.0 (RPSL-1.0) |
