Open source software license list

OSI Approved License Logo

About Open Source Licenses

Open source licenses are licenses that comply with the Open Source Definition — in brief, they allow software to be freely used, modified, and shared. To be approved by the Open Source Initiative (also known as the OSI), a license must go through the Open Source Initiative’s license review process.

Popular Licenses

The following OSI-approved licenses are popular, widely used, or have strong communities:

All Approved Licenses

Many other licenses are also OSI-approved, but fall into other categories, such as special-purpose licenses, superseded licenses, or retired licenses. Complete lists that include all approved licenses are available:


The OSI maintains a FAQ, which includes a lot of useful background on open source licensing, including:

For more information about open source licenses and in particular about the Open Source Initiative’s approval process, see:

Wikimedia list article

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.[1] The Free Software Foundation (FSF) maintains a list of what it considers free.[2] 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.[3][4] The OSI does not endorse FSF license analysis (interpretation) as per their disclaimer.[5]

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.[6][7] 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.[8] Yet, many FOSS licenses, like the Apache License, and all Free Software licenses allow commercial use of FOSS components.[9]

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,[10] 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.

Other licenses that don’t have information:





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.

  1. ^

    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.

  2. ^

    But can be made compatible by upgrading to GPLv3 via the optional “or later” clause added in most GPLv2 license texts.

  3. ^

    But not with GPLv2 without “or later” clause.

  4. ^

    MPL 2.0 is GPL compatible unless marked “Incompatible with Secondary Licenses”.

  5. ^

    Listed as WTFPL.

See also








SPDX License List

The SPDX License List is an integral part of the SPDX Specification. The SPDX License List itself is a list of commonly found licenses and exceptions used in free and open or collaborative software, data, hardware, or documentation. The SPDX License List includes a standardized short identifier, the full name, the license text, and a canonical permanent URL for each license and exception.

The purpose of the SPDX License List is to enable efficient and reliable identification of such licenses and exceptions in an SPDX document, in source files or elsewhere.

Version: 3.18 2022-08-12

Note: You can sort by each column by clicking on the column header. By default, the table sorts by the Identifier column.

Deprecated License Identifiers

Note: You can sort by each column by clicking on the column header. By default, the table sorts by the Identifier column.

SPDX endeavors to never change the SPDX license identifiers. However, sometimes there has been a compelling reason to deprecate a license identifier, such as to accommodate improved SPDX license expressions or when we have found a duplicate license. When a license identifier is “deprecated” on the SPDX License List, it effectively means that there is an updated license identifier and the deprecated license identifier, while remaining valid, should no longer be used. The URL to each deprecated license is retained and those license pages are updated to note the deprecation. Some reasons for deprecation are as follows:

  • Release 2.0 of the SPDX Specification introduced License Expressions that supports the ability to identify common variations of SPDX-identified licenses without the need to define each potential variation as a distinct license on the SPDX License List. This new syntax supports the ability to declare an SPDX-identified license exception using the “WITH” operator (e.g. GPL-2.0-or-later WITH Autoconf-exception-2.0), as well as the ability to use a simple “+” operator after a license short identifier to indicate “or later version”. SPDX has defined a list of license exceptions to use after the “WITH” operator. As a result, a number of licenses formerly included on the SPDX License List have been deprecated, and correct usage employs the License Expression syntax as of v2.0.
  • Release 3.0 replaced previous Identifiers for GNU licenses with more explicit Identifiers to reflect the “this version only” or “any later version” option specific to those licenses. As such, the previously used Identifiers for those licenses are deprecated as of v3.0.
  • Other licenses may have been deprecated for the reasons noted.

OSI Approved License Logo

License Index

  • License Approval Process
  • License Information
  • Origins and definitions of categories from the License Proliferation Committee report

In the lists below, a parenthesized expression following a license name is its SPDX short identifier, if one exists, except for two items in the first list (GNU General Public License and GNU Lesser General Public License). For these, the parenthesized expressions (“GPL” and “LGPL” respectively) are the common non-version-specific names of these licenses today (note also that the full name of the first version (2.0) of the LGPL is the GNU Library General Public License). There is no non-version-specific SPDX short identifier for the GPL and LGPL.

Licenses that are “popular and widely-used or with strong communities”

The below list is based on publicly available statistics obtained at the time of the Report of License Proliferation Committee.

International licenses

Special purpose licenses

Certain licensors, such as schools and the US government, have specialized concerns, such as specialized rules for government copyrights. Licenses that were identified by the License Proliferation Committee as meeting a special need were placed in this group.

Other/Miscellaneous licenses

    These licenses do not fall neatly into any category.

Licenses that are redundant with more popular licenses

Several licenses in this group are excellent licenses and have their own followings, however these licenses were perceived by the License Proliferation Committee as completely or partially redundant with existing licenses.

Non-reusable licenses

Licenses in this group are specific to their authors and cannot be reused by others. Many, but not all, of these licenses fall into the category of vanity licenses.

Superseded licenses

Licenses in this category have been superseded by newer versions.

Licenses that have been voluntarily retired

Self-defining category. No one should use these licenses going forward, although we assume that licensors may or may not choose to continue to use them.

Uncategorized Licenses

Written by Jane