Source-available software

{{short description|Software licensed to ensure access to source code}} {{primary sources|date=July 2011}} {{Use dmy dates|date=February 2026}}

'''Source-available software''' is software released through a source code distribution model that includes arrangements where the source can be viewed, and in some cases modified, but without necessarily meeting the criteria to be called ''open-source''.<ref name="dod">{{cite web|url=https://dodcio.defense.gov/Open-Source-Software-FAQ/|title=DoD Open Source Software (OSS) FAQ: Is there a name for software whose source code is publicly available, but does not meet the definition of open source software? |website=Chief Information Officer|publisher=U.S. Department of Defense|access-date=23 July 2018|archive-url=https://web.archive.org/web/20180724032116/https://dodcio.defense.gov/Open-Source-Software-FAQ/|archive-date=24 July 2018}}</ref> The licenses associated with the offerings range from allowing code to be viewed for reference to allowing code to be modified and redistributed for both commercial and non-commercial purposes.<ref name="Fortunato-2021">{{Cite Q|Q111919147|osti-access=free|via=OSTI|pages=7–8, 10|access-date=5 February 2026}}</ref>

Some source-available software licenses, classified as ''noncompete licenses'', are closed-source software licenses that have been created by modifying an open-source software license to include a restriction that prohibits using the licensed software to compete with the developer.<ref name="Riehle-2023">{{cite magazine |last1=Riehle |first1=Dirk |title=The Future of the Open Source Definition |magazine=Computer |date=16 November 2023 |volume=56 |issue=12 |pages=95–99 |doi=10.1109/MC.2023.3311648 |doi-access=free |url=https://ieeexplore.ieee.org/document/10319889 |access-date=5 February 2026 |issn=1558-0814}}</ref> These anti-competitive restrictions create a vendor lock-in effect by steering users toward establishing a separate agreement with the developer for commercial use of the software.<ref name="Kshetri-2025">{{cite magazine |last1=Kshetri |first1=Nir |title=Economics of Open Source Software and AI Models |magazine=Computer |date=8 January 2025 |volume=58 |issue=1 |pages=134–141 |doi=10.1109/MC.2024.3488974 |doi-access=free |url=https://ieeexplore.ieee.org/abstract/document/10834152 |access-date=5 February 2026 |issn=1558-0814}}</ref>

== Distinction from free and open-source software == Any software is ''source-available'' in the broad sense as long as its source code is distributed along with it, even if the user has no legal rights to use, share, modify or even compile it. It is possible for a software to be both source-available software and proprietary software (e.g. id Software's ''Doom'').

In contrast, the definitions of free software and open-source software are much narrower. Free software and/or open-source software is also always ''source-available software'', but not all source-available software is also free software and/or open-source software. This is because the official definitions of those terms require considerable additional rights as to what the user can do with the available source (including, typically, the right to use said software, with attribution, in derived commercial products).<ref>{{cite web |title=The Open Source Definition {{!}} Open Source Initiative |url=https://opensource.org/osd |website=opensource.org}}</ref>

In the broad sense, any FOSS license is a ''source-available'' license. In the narrow sense,<ref name="dod"/> the term ''source-available'' specifically excludes FOSS software.

== Non-free licenses == The following source-available software licenses are considered non-free licenses because they have limitations that prevent them from being open-source according to the Open Source Initiative and free to the Free Software Foundation.

=== Commons Clause ===

The Commons Clause, created by Fossa, Inc., is an addendum to an open-source software license that restricts users from selling the software. Under the combined license, the software is source-available, but not open-source.<ref name="Kabakoff-2019">{{cite magazine |last1=Kabakoff |first1=Stephen E. |last2=Petrella |first2=Nicholas D. |date=November–December 2019 |title=Why Open Source Licenses with a Commons Clause May Become Less Common |volume=12 |issue=2 |url=https://www.finnegan.com/en/insights/articles/why-open-source-licenses-with-a-commons-clause-may-become-less-common.html |magazine=Landslide |publisher=American Bar Association |access-date=5 February 2026 |via=Finnegan}}</ref><ref name="Commons Clause License">{{cite web|access-date=24 August 2018|title=Commons Clause License|url=https://commonsclause.com/|website=Commons Clause License}}</ref>

On 22 August 2018, Redis Labs shifted some Redis Modules from the GNU Affero General Public License<ref>{{cite news|access-date=24 August 2018|title=Why Redis Labs' Modules are AGPL |website=Redis Labs|url=https://redislabs.com/blog/why-redis-labs-modules-are-agpl/|date=5 July 2016|last=Shoolman|first=Yiftach}}</ref><ref>{{cite news|access-date=24 August 2018|title=Redis has a license to kill: Open-source database maker takes some code proprietary|url=https://www.theregister.co.uk/2018/08/23/redis_database_license_change/|website=The Register|last=Claburn|first=Thomas}}</ref> to a combination of the Apache License 2.0 and the Commons Clause.<ref name="Commons Clause License"/><ref>{{cite news|access-date=24 August 2018|title=Why Redis Labs made a huge mistake when it changed its open source licensing strategy|url=https://www.techrepublic.com/article/why-redis-labs-made-a-huge-mistake-when-it-changed-its-open-source-licensing-strategy/|newspaper=TechRepublic|last=Asay|first=Matt}}</ref>

In September 2018, Matthew Garrett criticized Commons Clause calling it an "older way of doing things" and said it "doesn't help the commons".<ref>[https://mjg59.dreamwidth.org/51177.html The Commons Clause doesn't help the commons] Matthew Garrett's blog</ref>

=== Business Source License === {{further|Business Source License}} Business Source License has been introduced by MariaDB Corporation in 2016 and rapidly became one of the most adopted "delayed open source" licenses.<ref>{{cite web|url=https://opensource.org/delayed-open-source-publication|title=Delayed Open Source Publication|website=Open Source Initiative|access-date=25 February 2024}}</ref> It prohibits use of the code in production environments, where a commercial license is required.<ref>{{cite web|url=https://mariadb.com/bsl-faq-adopting/|title=Adopting and Developing BSL Software|website=MariaDB|access-date=25 February 2024}}</ref>

=== Functional Source License === Functional Source License has been introduced in November 2023 by Sentry, as a simpler alternative to Business Source License.<ref>{{cite web|url=https://blog.sentry.io/introducing-the-functional-source-license-freedom-without-free-riding/|title=Introducing the Functional Source License: Freedom without Free-riding|website=Sentry's blog|date=17 November 2023 |access-date=25 February 2024}}</ref> It prohibits any "competing" use of the code, to preserve the rights of the author to economically exploit it, but applies for a limited time, after which the code itself is considered to be available under Apache License or MIT License.<ref>{{cite web|url=https://fsl.software/|title=FSL - Functional Source License|website=Functional Source License|access-date=25 February 2024}}</ref>

=== {{anchor|GitLab Enterprise Edition License}} GitLab Enterprise Edition License (EE License) ===

The GitLab Enterprise Edition License is used exclusively by GitLab's commercial offering.<ref name="EE License">{{cite web|url=https://gitlab.com/gitlab-org/gitlab-ee/blob/master/LICENSE|title=The GitLab Enterprise Edition (EE) license (the "EE License")|website=GitLab|publisher=GitLab Inc.|date=16 May 2018|access-date=23 July 2018}}</ref> GitLab Inc. openly discloses that the EE License makes their Enterprise Edition product "proprietary, closed source code."<ref name="GitLab blog July 2016">{{cite web|url=https://about.gitlab.com/2016/07/20/gitlab-is-open-core-github-is-closed-source/|title=GitLab is open core, GitHub is closed source|last=Sijbrandij|first=Sid|website=GitLab|publisher=GitLab Inc.|date=20 July 2016|access-date=23 July 2018}}</ref> GitLab also releases an open-source Community Edition under the MIT License.<ref name="CE License">{{cite web|url=https://gitlab.com/gitlab-org/gitlab-ce/blob/master/LICENSE|title=GitLab Community Edition LICENSE file|website=GitLab|publisher=GitLab Inc.|date=15 May 2018|access-date=23 July 2018}}</ref> This makes GitLab an example of an open core company.

=== Mega Limited Code Review Licence === {{further|Mega (service)#History}} In 2016, Mega Ltd. released the source code of their Mega clients under the Mega Limited Code Review Licence, which only permits usage of the code "for the purposes of review and commentary".<ref>{{cite web|access-date=24 August 2018|date=7 September 2017|title=meganz/MEGAsync|url=https://github.com/meganz/MEGAsync/blob/master/LICENCE.md|website=GitHub}}</ref> The source code was released before former director Kim Dotcom stated that he would "create a Mega competitor that is completely open source and non-profit" following his departure from Mega Ltd.<ref>{{cite web|access-date=24 August 2018|date=30 July 2015|title=Interviews: Kim Dotcom Answers Your Questions - Slashdot|url=https://yro.slashdot.org/story/15/07/27/200204/interviews-kim-dotcom-answers-your-questions|website=yro.slashdot.org}}</ref><ref>{{cite news|access-date=24 August 2018|date=31 July 2015|title=Kim Dotcom promises to launch an open-source competitor to Mega (updated)|url=https://www.engadget.com/2015/07/31/kim-dotcom-new-site-mega/|newspaper=Engadget}}</ref>

=== Microsoft Shared Source Initiative === {{further|Shared Source Initiative#Restricted licenses}} Microsoft's Shared Source Initiative, launched in May 2001, comprises 5 licenses, 2 of which are open-source and 3 of which are restricted. The restricted licenses under this scheme are the Microsoft Limited Public License (Ms-LPL),<ref>{{cite web |url=http://www.microsoft.com/resources/sharedsource/licensingbasics/limitedpubliclicense.mspx |title=Microsoft Limited Public License (Ms-LPL) |website=Microsoft }}</ref> the Microsoft Limited Reciprocal License (Ms-LRL),<ref>{{cite web |url=http://www.microsoft.com/resources/sharedsource/licensingbasics/limitedreciprocallicense.mspx |title=Microsoft Limited Reciprocal License (Ms-LRL) |website=Microsoft }}</ref> and the Microsoft Reference Source License (Ms-RSL).<ref name="reference">{{cite web | url=http://referencesource.microsoft.com/license.html | title=Microsoft Reference Source License | publisher=Microsoft | date=6 July 2016 | quote=''"Reference use" means use of the software within your company as a reference, in read-only form, for the sole purposes of debugging your products, maintaining your products, or enhancing the interoperability of your products with the software, and specifically excludes the right to distribute the software outside of your company.'' | access-date=6 July 2016}}</ref>

=== Old Scilab License === {{further|Scilab#License}} Prior to version 5, Scilab described itself as "the open source platform for numerical computation"<ref>{{cite web | url=http://www.scilab.org | title=The open source platform for numerical computation | publisher=INRIA | access-date=4 January 2008 }}</ref> but had a license<ref>{{cite web | url=http://www.scilab.org/legal/license.html | archive-url=https://web.archive.org/web/20051212214843/http://www.scilab.org/legal/license.html | url-status=dead | archive-date=12 December 2005 | title=SCILAB License | publisher=INRIA | access-date=4 January 2008 }}</ref> that forbade commercial redistribution of modified versions. Versions 5 and later are distributed under the GPL-compatible CeCILL license.

=== Server Side Public License === {{further|Server Side Public License}} The Server Side Public License is a modification of the GNU Affero General Public License created by the MongoDB project. It modifies a clause relating to usage of the licensed work over a network, stating that if SSPL-licensed software is incorporated into a "service" offered to other users, the source code for the entirety of the service (including without limitation all software and APIs that would be required for a user to run an instance of the service themselves) must be released under the SSPL.<ref>{{Cite web|url=https://arstechnica.com/information-technology/2019/10/is-the-software-world-taking-too-much-from-the-open-source-community/|title=In 2019, multiple open source companies changed course—is it the right move?|first=Ars|last=Staff|date=16 October 2019|website=Ars Technica}}</ref> The license is considered non-free by the Open Source Initiative, Debian and Red Hat, as it contains conditions that are unduly discriminatory towards commercial use of the software.<ref>{{Cite web|url=https://www.zdnet.com/article/mongodb-open-source-server-side-public-license-rejected/|title=MongoDB "open-source" Server Side Public License rejected|last=Vaughan-Nichols|first=Steven J.|website=ZDNet|language=en|access-date=17 January 2019|archive-url=https://web.archive.org/web/20190116202120/https://www.zdnet.com/article/mongodb-open-source-server-side-public-license-rejected/|archive-date=16 January 2019|url-status=live}}</ref><ref>{{Cite web|url=https://www.geekwire.com/2019/mongodbs-licensing-changes-led-red-hat-drop-database-latest-version-server-os/|title=MongoDB's licensing changes led Red Hat to drop the database from the latest version of its server OS|date=16 January 2019|website=GeekWire|language=en-US|access-date=17 January 2019|archive-url=https://web.archive.org/web/20190117035708/https://www.geekwire.com/2019/mongodbs-licensing-changes-led-red-hat-drop-database-latest-version-server-os/|archive-date=17 January 2019|url-status=live}}</ref>

=== Open Compensation Token License === The Open Compensation Token License<ref>{{cite web |title=OCT License Text Repository |website=GitHub |url=https://github.com/open-compensation-token-license/license|access-date=24 March 2025}}</ref> is commercial source-available software license. The key idea is to keep software extendable by everyone and to combine this with fair payment. Commercial uses of the software require commercial licensing and the funds are distributed via technical means to the contributors. The German company iunera<ref>{{Cite web|url=https://www.iunera.com/kraken/big-data-examples/how-nfts-and-ai-can-solve-public-transport-challenges/|title=How NFTs and AI can solve Public Transport challenges|date=24 March 2025|website=iunera company blog}}</ref> created the license during a project to optimize public transport usage.<ref>{{Cite web|url=https://bmdv.bund.de/SharedDocs/DE/Artikel/DG/mfund-projekte/fahrbar20.html/|title=Künstliche Intelligenz basierte Belegungsoptimierung im ÖPNV – Fahrbar20|date=24 March 2025|website=German Federal Ministry for Digital and Transport }}</ref> The license works by registering source code artifacts as code tokens on the blockchain. Every developer who builds on prior software needs to register the dependencies that he or she uses via the blockchain. This ensures that the prior labor by other developers is acknowledged. Commercial applications require an obtaining a license via the blockchain. The license cost is computed as a percentage of the invested work hours. Licensing funds are distributed based on the dependencies to the code token owners via blockchain. Anyone who extends source code which is licensed with the Open Compensation Token License is required to use the same license. The license webpage<ref>{{cite web |title=OCT License Project Website |url=https://www.license-token.com/|access-date=24 March 2025}}</ref> is explicitly stating it is non Open Source.

=== SugarCRM Public License === {{further|SugarCRM#License}} In 2007 Michael Tiemann, president of OSI, had criticized<ref>{{cite web | url=http://www.opensource.org/node/163 | title=Will The Real Open Source CRM Please Stand Up? | first=Michael | last=Tiemann | author-link=Michael Tiemann | date=21 June 2007 | publisher=Open Source Initiative | access-date=4 January 2008}}</ref> companies such as SugarCRM for promoting their software as "open source" when in fact it did not have an OSI-approved license. In SugarCRM's case, it was because the software is so-called "badgeware"<ref>{{cite web | url=http://blogs.zdnet.com/BTL/index.php?p=3430 | date=21 November 2006 | title=Are SugarCRM, Socialtext, Zimbra, Scalix and others abusing the term "open source?" | first=David | last=Berlind | publisher=ZDNet | access-date=4 January 2008 | url-status=dead | archive-url=https://web.archive.org/web/20080101010337/http://blogs.zdnet.com/BTL/index.php?p=3430 | archive-date=1 January 2008 | df=dmy-all }}</ref> since it specified a "badge" that must be displayed in the user interface. SugarCRM's open source version was re-licensed under the GPL version 3 in 2007,<ref>{{cite news|last=Vance|first=Ashlee|author-link=Ashlee Vance|date=25 July 2007|title=SugarCRM trades badgeware for GPL 3|publisher=The Register|url=http://www.regdeveloper.co.uk/2007/07/25/sugarcrm_gpl3/|access-date=8 September 2008}}</ref> and later the GNU Affero GPL version 3 in 2010.<ref name=":2">{{cite web|author1=OSI Board of Directors|date=19 January 2021|title=The SSPL is Not an Open Source License|url=https://opensource.org/node/1099|access-date=23 January 2021|publisher=Open Source Initiative}}</ref>

=== TrueCrypt License === {{further|TrueCrypt#License and source model}} The TrueCrypt License was used by the TrueCrypt disk encryption utility.<ref name="truecrypt-archive">{{cite web|url=https://github.com/DrWhax/truecrypt-archive/blob/master/doc/License-v3.1.txt|title=truecrypt-archive/License-v3.1.txt at master · DrWhax/truecrypt-archive|website=GitHub|date=28 March 2014|access-date=23 July 2018}}</ref> When TrueCrypt was discontinued, the VeraCrypt fork switched to the Apache License, but retained the TrueCrypt License for code inherited from TrueCrypt.<ref name="VeraCrypt license">{{cite web|url=https://www.veracrypt.fr/code/VeraCrypt/tree/License.txt?h=VeraCrypt_1.19|title=root/License.txt|website=VeraCrypt|publisher=TrueCrypt Foundation|date=17 October 2016|access-date=23 July 2018}}</ref>

The Open Source Initiative rejects the TrueCrypt License, as "it has elements incompatible with the OSD."<ref name=Phipps>{{Citation | last =Phipps | first =Simon | author-link =Simon Phipps (programmer) | title =TrueCrypt or false? Would-be open source project must clean up its act | publisher =InfoWorld | date =15 November 2013 | url = http://www.infoworld.com/d/open-source-software/truecrypt-or-false-would-be-open-source-project-must-clean-its-act-230862 | access-date = 20 May 2014}}</ref> The Free Software Foundation criticizes the license for restricting who can execute the program, and for enforcing a trademark condition.<ref name="FSFLicenseList">{{cite web|url=https://www.gnu.org/licenses/license-list.html|title=Various Licenses and Comments about Them|website=GNU Operating System|publisher=Free Software Foundation|access-date=23 July 2018}}</ref>

=== BeeGFS End User License Agreement === BeeGFS EULA is the license of the distributed parallel file system BeeGFS, except the client for Linux, which is licensed under GPLv2.<ref>{{cite web|url=https://www.beegfs.io/content/documentation/#eula|title=BeeGFS End User License Agreement - Documentation - BeeGFS|website=BeeGFS|access-date=8 June 2020}}</ref>

BeeGFS source code is publicly available from their website,<ref>{{cite web|url=https://www.beegfs.io/source|title=GitLab|website=BeeGFS|access-date=8 June 2020}}</ref> and because of this they claim that BeeGFS as "Open-Source" software;<ref>{{cite web|url=https://www.beegfs.io/wiki/FAQ#open_source|title=Frequently Asked Questions (FAQ)|website=BeeGFS Wiki|access-date=8 June 2020}}</ref> it is in fact not because this license prohibits distributing modified versions of the software, or using certain features of the software without authorization.<ref>{{cite web |title=End-User License Agreement |url=https://www.beegfs.io/docs/BeeGFS_EULA.txt |access-date=26 January 2021 |format=plain text |date=10 September 2019}}</ref>

==References== {{reflist|30em}}

{{DEFAULTSORT:Source-available software}} Category:Software licensing