Comparison of free and open-source software licenses

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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.

Contents

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 to 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:

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:

licenseAuthorLatest versionPublication date
Eiffel Forum License NICE22002
Intel Open Source License Intel Corporation — ?
RealNetworks Public Source License RealNetworks  ? ?
Reciprocal Public License Scott Shattuck1.52007
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 1.02018-10-16

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.

  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

Notes

  1. ↑ See footnote of the Beerware article

Related Research Articles

<span class="mw-page-title-main">Free software</span> Software licensed to be freely used, modified and distributed

Free software, libre software, libreware sometimes known as freedom-respecting software is computer software distributed under terms that allow users to run the software for any purpose as well as to study, change, and distribute it and any adapted versions. Free software is a matter of liberty, not price; all users are legally free to do what they want with their copies of a free software regardless of how much is paid to obtain the program. Computer programs are deemed "free" if they give end-users ultimate control over the software and, subsequently, over their devices.

The free software movement is a social movement with the goal of obtaining and guaranteeing certain freedoms for software users, namely the freedoms to run, study, modify, and share copies of software. Software which meets these requirements, The Four Essential Freedoms of Free Software, is termed free software.

<span class="mw-page-title-main">GNU Lesser General Public License</span> Free-software license

The GNU Lesser General Public License (LGPL) is a free-software license published by the Free Software Foundation (FSF). The license allows developers and companies to use and integrate a software component released under the LGPL into their own software without being required by the terms of a strong copyleft license to release the source code of their own components. However, any developer who modifies an LGPL-covered component is required to make their modified version available under the same LGPL license. For proprietary software, code under the LGPL is usually used in the form of a shared library, so that there is a clear separation between the proprietary and LGPL components. The LGPL is primarily used for software libraries, although it is also used by some stand-alone applications.

The MIT License is a permissive software license originating at the Massachusetts Institute of Technology (MIT) in the late 1980s. As a permissive license, it puts very few restrictions on reuse and therefore has high license compatibility.

<span class="mw-page-title-main">Apache License</span> Free software license

The Apache License is a permissive free software license written by the Apache Software Foundation (ASF). It allows users to use the software for any purpose, to distribute it, to modify it, and to distribute modified versions of the software under the terms of the license, without concern for royalties. The ASF and its projects release their software products under the Apache License. The license is also used by many non-ASF projects.

The Open Software License (OSL) is a software license created by Lawrence Rosen. The Open Source Initiative (OSI) has certified it as an open-source license, but the Debian project judged version 1.1 to be incompatible with the DFSG. The OSL is a copyleft license, with a termination clause triggered by filing a lawsuit alleging patent infringement.

The Apple Public Source License (APSL) is the open-source and free software license under which Apple's Darwin operating system was released in 2000. A free and open-source software license was voluntarily adopted to further involve the community from which much of Darwin originated.

The Common Development and Distribution License (CDDL) is a free and open-source software license, produced by Sun Microsystems, based on the Mozilla Public License (MPL). Files licensed under the CDDL can be combined with files licensed under other licenses, whether open source or proprietary. In 2005 the Open Source Initiative approved the license. The Free Software Foundation (FSF) considers it a free software license, but one which is incompatible with the GNU General Public License (GPL).

<span class="mw-page-title-main">Free and open-source software</span> Software whose source code is available and which is permissively licensed

Free and open-source software (FOSS) is software that is available under a license that grants the right to use, modify, and distribute the software, modified or not, to everyone free of charge. The public availability of the source code is, therefore, a necessary but not sufficient condition. FOSS is an inclusive umbrella term for free software and open-source software. FOSS is in contrast to proprietary software, which consists of software under restrictive copyright or licensing as well as software with undisclosed source code.

A permissive software license, sometimes also called BSD-like or BSD-style license, is a free-software license which instead of copyleft protections, carries only minimal restrictions on how the software can be used, modified, and redistributed, usually including a warranty disclaimer. Examples include the GNU All-permissive License, MIT License, BSD licenses, Apple Public Source License and Apache license. As of 2016, the most popular free-software license is the permissive MIT license.

Alternative terms for free software, such as open source, FOSS, and FLOSS, have been a controversial issue among free and open-source software users from the late 1990s onwards. These terms share almost identical licence criteria and development practices.

The Sybase Open Watcom Public License is a software license that has been approved by the Open Source Initiative. It is the licence under which the Open Watcom C/C++ compiler is released.

<span class="mw-page-title-main">Public-domain-equivalent license</span> License that waives all copyright

Public-domain-equivalent license are licenses that grant public-domain-like rights and/or act as waivers. They are used to make copyrighted works usable by anyone without conditions, while avoiding the complexities of attribution or license compatibility that occur with other licenses.

License proliferation is the phenomenon of an abundance of already existing and the continued creation of new software licenses for software and software packages in the FOSS ecosystem. License proliferation affects the whole FOSS ecosystem negatively by the burden of increasingly complex license selection, license interaction, and license compatibility considerations.

License compatibility is a legal framework that allows for pieces of software with different software licenses to be distributed together. The need for such a framework arises because the different licenses can contain contradictory requirements, rendering it impossible to legally combine source code from separately-licensed software in order to create and publish a new program. Proprietary licenses are generally program-specific and incompatible; authors must negotiate to combine code. Copyleft licenses are commonly deliberately incompatible with proprietary licenses, in order to prevent copyleft software from being re-licensed under a proprietary license, turning it into proprietary software. Many copyleft licenses explicitly allow relicensing under some other copyleft licenses. Permissive licenses are compatible with everything, including proprietary licenses; there is thus no guarantee that all derived works will remain under a permissive license.

<span class="mw-page-title-main">GNU Affero General Public License</span> Free software license based on the AGPLv1 and GPLv3

The GNU Affero General Public License is a free, copyleft license published by the Free Software Foundation in November 2007, and based on the GNU GPL version 3 and the Affero General Public License (non-GNU).

<span class="mw-page-title-main">Free-software license</span> License allowing software modification and redistribution

A free-software license is a notice that grants the recipient of a piece of software extensive rights to modify and redistribute that software. These actions are usually prohibited by copyright law, but the rights-holder of a piece of software can remove these restrictions by accompanying the software with a software license which grants the recipient these rights. Software using such a license is free software as conferred by the copyright holder. Free-software licenses are applied to software in source code and also binary object-code form, as the copyright law recognizes both forms.

BSD licenses are a family of permissive free software licenses, imposing minimal restrictions on the use and distribution of covered software. This is in contrast to copyleft licenses, which have share-alike requirements. The original BSD license was used for its namesake, the Berkeley Software Distribution (BSD), a Unix-like operating system. The original version has since been revised, and its descendants are referred to as modified BSD licenses.

<span class="mw-page-title-main">GNU General Public License</span> Series of free software licenses

The GNU General Public Licenses are a series of widely used free software licenses, or copyleft licenses, that guarantee end users the freedoms to run, study, share, and/or modify the software. The GPL was the first copyleft license available for general use. It was originally written by Richard Stallman, the founder of the Free Software Foundation (FSF), for the GNU Project. The license grants the recipients of a computer program the rights of the Free Software Definition. The licenses in the GPL series are all copyleft licenses, which means that any derivative work must be distributed under the same or equivalent license terms. It is more restrictive than the Lesser General Public License, and even further distinct from the more widely-used permissive software licenses such as BSD, MIT, and Apache.

Software relicensing is applied in open-source software development when software licenses of software modules are incompatible and are required to be compatible for a greater combined work. Licenses applied to software as copyrightable works, in source code as binary form, can contain contradictory clauses. These requirements can make it impossible to combine source code or content of several software works to create a new combined one.

References

  1. ↑ Open source licenses - Licenses by Name on opensource.org
  2. ↑ "Various Licenses and Comments about Them". Free Software Foundation. Retrieved August 8, 2011.
  3. ↑ "Various Licenses and Comments about Them: NASA Open Source Agreement". Free Software Foundation.
  4. ↑ "Licenses by Name". Open Source Initiative. 16 September 2022.
  5. ↑ "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.
  6. ↑ "Relationship between the Free Software movement and Open Source movement", Free Software Foundation, Inc
  7. ↑ "What is Free Software", Free Software Foundation, Inc
  8. ↑ 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."
  9. ↑ Popp, Dr. Karl Michael (2015). Best Practices for commercial use of open source software. Norderstedt, Germany: Books on Demand. ISBN   978-3738619096.
  10. ↑ "Joinup Licensing Assistant" . Retrieved 31 March 2020.
  11. 1 2 "OSL 3.0 Explained".
  12. ↑ "affero.org: Affero General Public License version 1 (AGPLv1)". Archived from the original on November 23, 2019.
  13. 1 2 3 "affero.org: Affero General Public License version 2 (AGPLv2)". Archived from the original on November 23, 2019.
  14. 1 2 3 4 5 6 7 "the section 4 of the apache license version 2".
  15. 1 2 3 4 5 6 7 "BSD license". 22 May 2011.
  16. ↑ "Using CC0 for public domain software". Creative Commons. April 15, 2011. Archived from the original on May 14, 2011. Retrieved May 10, 2011.
  17. ↑ "Various Licenses and Comments about Them". GNU Project . Retrieved April 4, 2015.
  18. 1 2 cc-by-4-0-and-cc-by-sa-4-0-added-to-our-list-of-free-licenses (2015)
  19. ↑ "Compatible Licenses". Creative Commons.
  20. 1 2 3 4 5 6 7 "Eclipse Public License - v 2.0".
  21. ↑ "How to Use Popular Open Source Licenses, Explained".
  22. ↑ 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.
  23. 1 2 3 4 "EUPL compatible open source licences".
  24. 1 2 3 "EUPL text (1.1 & 1.2)".
  25. 1 2 3 4 5 6 7 "FreeBSD license".
  26. 1 2 https://www.gnu.org/licenses/agpl.html  : section 13 of the GNU AGPLv3 license
  27. 1 2 3 4 5 6 7 8 9 https://www.gnu.org/copyleft/gpl-howto.html  : GNU licenses copyleft
  28. 1 2 3 "the GNU Affero General Public License version 3".
  29. ↑ https://www.gnu.org/licenses/gpl-faq.html#IfLibraryIsGPL  : If library is under GPLv3
  30. ↑ https://www.gnu.org/licenses/gpl-faq.html#LinkingWithGPL  : Linking with the GNU GPLv3
  31. 1 2 3 "the GNU General Public License version 3".
  32. ↑ https://www.gnu.org/licenses/lgpl.html  : the section 4 of the GNU Lesser General Public License version 3
  33. 1 2 "the GNU Lesser General Public License version 3".
  34. 1 2 3 4 5 6 7 "MIT License". 31 October 2006.
  35. 1 2 3 4 5 6 7 "MPL version 2".
  36. ↑ "PHP License 3.01".
  37. ↑ Free Software Foundation. "Various Licenses and Comments about Them". Licenses. Free Software Foundation.
  38. ↑ 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.
  39. ↑ Free Software Foundation. "GPL-Compatible Free Software Licenses – Free Software Foundation". Software Licenses. Free Software Foundation.
  40. ↑ Free Software Foundation. "GPL-Incompatible Free Software Licenses – Free Software Foundation". Software Licenses. Free Software Foundation.
  41. ↑ Free Software Foundation. "GPL-compatible Definition by FSF – Free Software Foundation". GPL-compatible Definition. Free Software Foundation.
  42. ↑ Free Software Foundation. "GPL-compatible Definition previous version by FSF – Free Software Foundation". GPL-compatible Definition. Free Software Foundation.
  43. ↑ Open Source Initiative (16 September 2022). "The Approved Licenses". License Information. Open Source Initiative.
  44. ↑ Debian. "Debian – License information". Licenses. Debian.
  45. ↑ "The DFSG and Software Licenses". Debian wiki.
  46. ↑ Fedora. "Licensing – FedoraProject". Licenses. Fedora Project.
  47. ↑ Free Software Foundation. "Apache License, Version 2.0". Licenses. Free Software Foundation.
  48. ↑ "Apple Public Source License (APSL), version 1.x" . Retrieved 2013-08-07.
  49. 1 2 "Various Licenses and Comments about Them". Free Software Foundation. 2016-01-05. Retrieved 2016-01-05.
  50. ↑ "Licensing/Beerware". Fedora Project . Retrieved 2015-03-10.
  51. ↑ "The BSD License:Licensing". Open Source Initiative. Archived from the original on 29 November 2009. Retrieved 1 February 2021.
  52. ↑ "[License-review] Please rename "Free Public License-1.0.0" to 0BSD". Open Source Initiative . Retrieved 2019-02-11.
  53. ↑ "Various Licenses and Comments About Them - Common Development and Distribution License". Free Software Foundation. Retrieved 2006-12-31.
  54. ↑ Michael Larabel (6 October 2015). "Ubuntu Is Planning To Make The ZFS File-System A "Standard" Offering". Phoronix.
  55. ↑ Dustin Kirkland (18 February 2016). "ZFS Licensing and Linux". Ubuntu Insights. Canonical.
  56. ↑ 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)
  57. ↑ Moglen, Eben; Choudhary, Mishi (26 February 2016). "The Linux Kernel, CDDL and Related Issues".
  58. ↑ GPL Violations Related to Combining ZFS and Linux on sfconservancy.org by Bradley M. Kuhn and Karen M. Sandler (February 25, 2016)
  59. 1 2 3 "Various Licenses and Comments about Them - GNU Project - Free Software Foundation".
  60. ↑ "Frequently Answered Questions". opensource.org. 21 October 2007. CC0 was not explicitly rejected, but the License Review Committee was unable to reach consensus that it should be approved
  61. 1 2 "Licensing:Main".
  62. ↑ "Creative Commons BY-SA 4.0 declared one-way compatible with GNU GPL version 3 — Free Software Foundation — working together for free software".
  63. ↑ Free Software Foundation. "Educational Community License 2.0". Licenses. Free Software Foundation.
  64. ↑ https://www.gnu.org/licenses/  : "We use only licenses that are compatible with the GNU GPL for GNU software."
  65. 1 2 "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.
  66. ↑ "Re: Proposed statement WRT GNU FDL".
  67. ↑ "SPDX License List | Software Package Data Exchange (SPDX)".
  68. ↑ "General Resolution: Why the GNU Free Documentation License is not suitable for Debian main".
  69. ↑ Free Software Foundation. "A Quick Guide to GPLv3". Licenses. Free Software Foundation.
  70. ↑ Mozilla Foundation. "MPL 2.0 FAQ". Licenses. Mozilla Foundation.
  71. ↑ "Various Licenses and Comments about Them - GNU Project - Free Software Foundation".
  72. ↑ "[License-review] Request for legacy approval: The Unlicense".
  73. ↑ "OSI Board Meeting Minutes, Wednesday, March 4, 2009". 4 May 2009.
  74. ↑ Free Software Foundation. "XFree86 1.1 License". Licenses. Free Software Foundation.
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