TheShared Source Initiative(SSI) is asource-availablesoftware licensingscheme launched byMicrosoftin May 2001.[1]The program includes a spectrum of technologies and licenses, and most of its source code offerings are available for download after eligibility criteria are met.[2][3]
Overview
editMicrosoft's Shared Source Initiative allows individuals and organizations to access Microsoft's source code for reference (e.g. when developing complementary systems), for review and auditing from a security perspective (mostly wanted by some large corporations and governments), and for development (academic institutions, OEMs, individual developers).
As part of the framework, Microsoft released 5 licenses for general use. Two of them,Microsoft Public LicenseandMicrosoft Reciprocal License,have been approved by theOpen Source Initiativeasopen source licenses[4][5]and are regarded by theFree Software Foundationasfree softwarelicenses.[6]Other shared source licenses are proprietary, and thus allow the copyright holder to retain tighter control over the use of their product.
Microsoft's Shared Source Initiative has been imitated by other companies such asRISC OS Open Ltd.[7]
Microsoft also uses specific licenses for some of their products, such as theShared Source CLILicense[8]and the MicrosoftWindows Embedded CE6.0 Shared Source License.[9]
Free and open-source licenses
editThe following licenses are consideredopen-sourceby theOpen Source Initiativeandfreeby theFree Software Foundation.
Microsoft Public License (Ms-PL)
editThis is the least restrictive of the Microsoft licenses and allows for distribution ofcompiledcode for either commercial or non-commercial purposes under any license that complies with the Ms-PL. Redistribution of the source code itself is permitted only under the Ms-PL.[10]Initially titledMicrosoft Permissive License,it was renamed toMicrosoft Public Licensewhile being reviewed for approval by theOpen Source Initiative(OSI).[11]The license was approved on October 12, 2007, along with the Ms-RL.[12] According to the Free Software Foundation, it is a free software license but not compatible with theGNU GPL.[6]Ms-PL provides a free and flexible licensing for developers using source codes under this license. However, the Ms-PL is acopyleftlicense because it requires the source code of software it governs to be distributed only under the same license (the Ms-PL).[13]
Microsoft Reciprocal License (Ms-RL)
editThis Microsoft license allows for distribution of derived code so long as the modified source files are included and retain the Ms-RL.[14]The Ms-RL allows those files in the distribution that do not contain code originally licensed under Ms-RL to be licensed according to the copyright holder's choosing. This is similar, but not the same as theCDDL,EPLorLGPL(GPL with a typical "linking exception" ).[citation needed]Initially known as theMicrosoft Community License,it was renamed during the OSI approval process.
On December 9, 2005, the Ms-RL license was submitted to theOpen Source Initiativefor approval by John Cowan.[15]OSI then contacted Microsoft and asked if they wanted OSI to proceed. Microsoft replied that they did not wish to be reactive and that they needed time to review such a decision.[16]
At theO'Reilly Open Source Conventionin July 2007,Bill Hilf,director of Microsoft's work with open source projects, announced that Microsoft had formally submitted Ms-PL and Ms-RL toOSIfor approval.[17]It was approved on October 12, 2007, along with the Ms-PL.[12]According to the Free Software Foundation, it is a free software license but not compatible with theGNU GPL.[6]
Restricted licenses
editThe followingsource-available softwarelicenses have limitations that prevent them from beingopen-sourceaccording to theOpen Source Initiativeandfreeto theFree Software Foundation.
Microsoft Limited Public License (Ms-LPL)
editThis is a version of the Microsoft Public License in which rights are only granted to developers ofMicrosoft Windows-based software.[18]This license is not open source, as defined by theOSI,because the restriction limiting use of the software to Windows violates the stipulation that open-source licenses must be technology-neutral.[19]It is also considered to be non-free by the Free Software Foundation due to this restriction.[6]
Microsoft Limited Reciprocal License (Ms-LRL)
editThis is a version of the Microsoft Reciprocal License in which rights are only granted when developing software for a Microsoft Windows platform.[20]Like the Ms-LPL, this license is not open source because it is not technology-neutral[19]due to its restriction that licensed software must be used on Windows, and is also not considered free by the Free Software Foundation due to this restriction.[6]
Microsoft Reference Source License (Ms-RSL)
editThis is the most restrictive of the Microsoft Shared Source licenses. The source code is made available to view for reference purposes only, mainly to be able to view Microsoft classes source code while debugging.[21]Developers may not distribute or modify the code for commercial or non-commercial purposes.[22]The license has previously been abbreviatedMs-RL,butMs-RLnow refers to theMicrosoft Reciprocal License.[14]
Criticism
editTwo specific shared source licenses are interpreted as free software and open source licenses byFSFandOSI.However, former OSI presidentMichael Tiemannconsiders the phrase "Shared Source" itself to be a marketing term created by Microsoft. He argues that it is "an insurgent term that distracts and dilutes the Open Source message by using similar-sounding terms and offering similar-sounding promises".[23]
The Shared Source Initiative has also been noted to increase the problem oflicense proliferation.[24]
See also
edit
References
edit- ^"Microsoft announces expansion of Shared Source Initiative".
- ^"Microsoft Shared Source Initiative".Berkman Klein Center.Retrieved24 Aug2018.
- ^iphome 11
- ^"Microsoft Public License (MS-PL) – Open Source Initiative".opensource.org.
- ^"Microsoft Reciprocal License (MS-RL) – Open Source Initiative".opensource.org.
- ^abcde"Various Licenses and Comments about Them".GNU Operating System.Free Software Foundation.Retrieved23 Jul2018.
- ^"RISC OS Open: Welcome".www.riscosopen.org.
- ^"Shared Source Common Language Infrastructure License".
- ^Archiveddocs."Windows Embedded".msdn2.microsoft.com.
- ^"Microsoft Public License (Ms-PL)".Microsoft.
- ^Foley, Mary."Microsoft gets the open-source licensing nod from the OSI".ZDNet.Retrieved22 May2015.
- ^ab"OSI Approves Microsoft License Submissions".2007-10-17.Retrieved2013-08-08.
Acting on the advice of the License Approval Chair, the OSI Board today approved the Microsoft Public License (Ms-PL) and the Microsoft Reciprocal License (Ms-RL). The decision to approve was informed by the overwhelming (though not unanimous) consensus from the open source community that these licenses satisfied the 10 criteria of the Open Source definition, and should therefore be approved.
- ^"Microsoft Public License (MS-PL) | Open Source Initiative".opensource.org.Retrieved2020-08-28.
- ^ab"Microsoft Reciprocal License (Ms-RL)".Microsoft.
- ^John Cowan (2005-12-09)."For Approval: Microsoft Community License".license-discuss mailing list.
- ^Peter Galli (2006-08-22)."Blogger Can't Tempt Microsoft To Drink OSI Kool-Aid".eWeek.
- ^Tim O'Reilly (2007-07-26)."Microsoft to Submit Shared Source Licenses to OSI".O'Reilly Radar.
- ^"Microsoft Limited Public License (Ms-LPL)".Microsoft.
- ^ab"The Open Source Definition".Open Source Initiative.
- ^"Microsoft Limited Reciprocal License (Ms-LRL)".Microsoft.
- ^"Microsoft Reference Source License".Microsoft. 2016-07-06.Retrieved2016-07-06.
"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.
- ^"Microsoft Reference Source License".
- ^Michael Tiemann(2007-11-11)."Who Is Behind" Shared Source "Misinformation Campaign?".Retrieved2011-03-12.
Shared source is a marketing term created and controlled by Microsoft. Shared source is not open source by another name. Shared source is an insurgent term that distracts and dilutes the Open Source message by using similar-sounding terms and offering similar-sounding promises. And to date, 'shared source' has been a marketing dud as far as Open Source is concerned.
- ^Evaluating Microsoft’s Shared Source licensesArs Technica, 2007