Shared source
Encyclopedia
Shared source is an umbrella term covering some of Microsoft
's legal mechanisms for software source code
distribution. Microsoft's Shared Source Initiative, launched in May 2001, includes a spectrum of technologies and licenses. Most of its source code offerings are available for download after eligibility criteria are met.
The licenses associated with the offerings range from being closed-source, allowing only viewing of the code for reference, to allowing it to be modified and redistributed for both commercial and non-commercial purposes.
As part of the framework, Microsoft released 5 licenses for general use. Two of them, Microsoft Public License and Microsoft Reciprocal License, have been approved by the Open Source Initiative
as open source
licenses and are regarded by the Free Software Foundation
as free software
licenses. 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 as RISC OS Open Ltd.
Microsoft also uses specific licenses for some of their products, for example the Shared Source CLI
License and the Microsoft Windows Embedded CE
6.0 Shared Source License.
and OSI
. However, OSI president Michael Tiemann
considers 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".
and Free by the Free Software Foundation
.
(OSI). The license was approved on October 12, 2007 along with the Ms-RL.
According to the Free Software Foundation, it is a free software license but not compatible with the GNU GPL.
or LGPL (GPL with a typical "linking exception"). Initially known as the Microsoft Community License, it was renamed during the OSI approval process.
On December 9, 2005, the Ms-RL license was submitted to the Open Source Initiative
for approval by John Cowan. 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.
At the O'Reilly Open Source Convention
in July 2007, Bill Hilf
, director of Microsoft's work with open source projects, announced that Microsoft had formally submitted Ms-PL and Ms-RL to OSI
for approval. It was approved on October 12, 2007 along with the Ms-PL. According to the Free Software Foundation, it is a free software license but not compatible with the GNU GPL.
and non-Free to the Free Software Foundation
.
-based software. This license is not open source, as defined by the OSI
, because the restriction limiting use of the software to Windows violates the stipulation that open-source licenses must be technology-neutral. It is also considered to be non-free by the Free Software Foundation due to this restriction.
according to the Free Software Foundation
, nor OSI
-approved open source
.
Microsoft Enterprise Source Licensing Program
Microsoft gives enterprise customers viewing access to some parts of some versions of the Microsoft Windows
operating system
s. The ESLP license agreement is among the most restrictive of the licenses associated with Shared Source programs, allowing no modifications of the code.
Microsoft Windows Academic Program
The Windows Academic Program provides universities worldwide with concepts, Windows kernel source code, and projects useful for integrating core Windows kernel technologies into teaching and research.
Microsoft Government Security Program
The Microsoft Government Security Program is an effort to assist national governments in evaluating the security of Windows and of other Microsoft products. Participating governments have access to the source code for current versions of Windows and Windows service packs, Windows Embedded CE, and Microsoft Office.
Most Valuable Professionals Source Licensing Program
Through this program, Microsoft makes Windows source code available to members of their "Most Valuable Professional"
program. MVPs are members of the developer and support community who have made significant public, volunteer contributions, primarily through participation in online forums. The MVP Source Licensing Program allows licensees to use the source code for debugging and support purposes, though it may not be used to aid in the development of a commercial product.
Microsoft Shared Source Common Language Infrastructure
The first widely-distributed Shared Source program was Shared Source CLI
, the Shared Source implementation of the Common Language Infrastructure
. The licensing permits non-commercial modification and distribution of the source code, as long as all distributions include the original license, or one encompassing the original terms.
according to the Free Software Foundation
and the Open Source Initiative
.
ASP.Net AJAX Control Toolkit
The ASP.NET AJAX Control Toolkit is a set of controls and extenders that use AJAX technologies to enable developers to improve the client experience on their web sites. The toolkit is licensed under the Microsoft Public license (MS-PL) and is available on CodePlex, Microsoft’s online community development portal for collaborative software development projects.
Microsoft
Microsoft Corporation is an American public multinational corporation headquartered in Redmond, Washington, USA that develops, manufactures, licenses, and supports a wide range of products and services predominantly related to computing through its various product divisions...
's legal mechanisms for software source code
Source code
In computer science, source code is text written using the format and syntax of the programming language that it is being written in. Such a language is specially designed to facilitate the work of computer programmers, who specify the actions to be performed by a computer mostly by writing source...
distribution. Microsoft's Shared Source Initiative, launched in May 2001, includes a spectrum of technologies and licenses. Most of its source code offerings are available for download after eligibility criteria are met.
The licenses associated with the offerings range from being closed-source, allowing only viewing of the code for reference, to allowing it to be modified and redistributed for both commercial and non-commercial purposes.
Overview
Shared Source programs allow 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 License and Microsoft Reciprocal License, have been approved by the Open Source Initiative
Open Source Initiative
The Open Source Initiative is an organization dedicated to promoting open source software.The organization was founded in February 1998, by Bruce Perens and Eric S. Raymond, prompted by Netscape Communications Corporation publishing the source code for its flagship Netscape Communicator product...
as open source
Open source
The term open source describes practices in production and development that promote access to the end product's source materials. Some consider open source a philosophy, others consider it a pragmatic methodology...
licenses and are regarded by the Free Software Foundation
Free Software Foundation
The Free Software Foundation is a non-profit corporation founded by Richard Stallman on 4 October 1985 to support the free software movement, a copyleft-based movement which aims to promote the universal freedom to create, distribute and modify computer software...
as free software
Free software
Free software, software libre or libre software is software that can be used, studied, and modified without restriction, and which can be copied and redistributed in modified or unmodified form either without restriction, or with restrictions that only ensure that further recipients can also do...
licenses. 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 as RISC OS Open Ltd.
Microsoft also uses specific licenses for some of their products, for example the Shared Source CLI
Shared Source Common Language Infrastructure
The Shared Source Common Language Infrastructure , previously codenamed Rotor, is Microsoft's shared source implementation of the CLI, the core of .NET. Although the SSCLI is not suitable for commercial use due to its license, it does make it possible for programmers to examine the implementation...
License and the Microsoft Windows Embedded CE
Windows CE
Microsoft Windows CE is an operating system developed by Microsoft for embedded systems. Windows CE is a distinct operating system and kernel, rather than a trimmed-down version of desktop Windows...
6.0 Shared Source License.
Criticism
Two specific Shared Source licenses are interpreted as free software and open source licenses by FSFFree Software Foundation
The Free Software Foundation is a non-profit corporation founded by Richard Stallman on 4 October 1985 to support the free software movement, a copyleft-based movement which aims to promote the universal freedom to create, distribute and modify computer software...
and OSI
Open Source Initiative
The Open Source Initiative is an organization dedicated to promoting open source software.The organization was founded in February 1998, by Bruce Perens and Eric S. Raymond, prompted by Netscape Communications Corporation publishing the source code for its flagship Netscape Communicator product...
. However, OSI president Michael Tiemann
Michael Tiemann
Michael Tiemann is Vice President of Open Source Affairs at Red Hat Inc, as well as President of the Open Source Initiative. He previously was the Chief Technical Officer of Red Hat...
considers 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".
Open Source, Free licenses
Two Microsoft Shared Source Licenses are considered as Open Source by the Open Source InitiativeOpen Source Initiative
The Open Source Initiative is an organization dedicated to promoting open source software.The organization was founded in February 1998, by Bruce Perens and Eric S. Raymond, prompted by Netscape Communications Corporation publishing the source code for its flagship Netscape Communicator product...
and Free by the Free Software Foundation
Free Software Foundation
The Free Software Foundation is a non-profit corporation founded by Richard Stallman on 4 October 1985 to support the free software movement, a copyleft-based movement which aims to promote the universal freedom to create, distribute and modify computer software...
.
Microsoft Public License (Ms-PL)
This is the least restrictive of the Microsoft licenses and allows for distribution of compiled code 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. Initially titled Microsoft Permissive License, it was renamed to Microsoft Public License while being reviewed for approval by the Open Source InitiativeOpen Source Initiative
The Open Source Initiative is an organization dedicated to promoting open source software.The organization was founded in February 1998, by Bruce Perens and Eric S. Raymond, prompted by Netscape Communications Corporation publishing the source code for its flagship Netscape Communicator product...
(OSI). The license was approved on October 12, 2007 along with the Ms-RL.
According to the Free Software Foundation, it is a free software license but not compatible with the GNU GPL.
Microsoft Reciprocal License (Ms-RL)
This Microsoft license allows for distribution of derived code so long as the modified source files are included and retain the Ms-RL. 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 equivalent to the CDDL, EPLEclipse Public License
The Eclipse Public License is an open source software license used by the Eclipse Foundation for its software. It replaces the Common Public License and removes certain terms relating to litigations related to patents....
or LGPL (GPL with a typical "linking exception"). Initially known as the Microsoft Community License, it was renamed during the OSI approval process.
On December 9, 2005, the Ms-RL license was submitted to the Open Source Initiative
Open Source Initiative
The Open Source Initiative is an organization dedicated to promoting open source software.The organization was founded in February 1998, by Bruce Perens and Eric S. Raymond, prompted by Netscape Communications Corporation publishing the source code for its flagship Netscape Communicator product...
for approval by John Cowan. 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.
At the O'Reilly Open Source Convention
O'Reilly Open Source Convention
The O'Reilly Open Source Convention is an annual convention for the discussion of free and open source software. It is organized by the publisher O'Reilly Media and is held each summer in the United States.-Notable events:...
in July 2007, Bill Hilf
Bill Hilf
Bill Hilf is the General Manager of product management for Microsoft's cloud computing platform, Windows Azure. Previously, he was General Manager of the Technical Computing group at Microsoft, which focuses on High Performance Computing, Parallel Computing, and Cloud Computing...
, director of Microsoft's work with open source projects, announced that Microsoft had formally submitted Ms-PL and Ms-RL to OSI
Open Source Initiative
The Open Source Initiative is an organization dedicated to promoting open source software.The organization was founded in February 1998, by Bruce Perens and Eric S. Raymond, prompted by Netscape Communications Corporation publishing the source code for its flagship Netscape Communicator product...
for approval. It was approved on October 12, 2007 along with the Ms-PL. According to the Free Software Foundation, it is a free software license but not compatible with the GNU GPL.
Non-Open Source, non-Free licenses
The other Microsoft Shared Source Licenses have various limitations that make them non-Open Source according to the Open Source InitiativeOpen Source Initiative
The Open Source Initiative is an organization dedicated to promoting open source software.The organization was founded in February 1998, by Bruce Perens and Eric S. Raymond, prompted by Netscape Communications Corporation publishing the source code for its flagship Netscape Communicator product...
and non-Free to the Free Software Foundation
Free Software Foundation
The Free Software Foundation is a non-profit corporation founded by Richard Stallman on 4 October 1985 to support the free software movement, a copyleft-based movement which aims to promote the universal freedom to create, distribute and modify computer software...
.
Microsoft Reference Source License (Ms-RSL)
This 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. Developers may not distribute or modify the code for commercial or non-commercial purposes. The license has previously been abbreviated Ms-RL, but Ms-RL now refers to the Microsoft Reciprocal License.Microsoft Limited Public License (Ms-LPL)
This is a version of the Microsoft Public License in which rights are only granted to developers of Microsoft WindowsMicrosoft Windows
Microsoft Windows is a series of operating systems produced by Microsoft.Microsoft introduced an operating environment named Windows on November 20, 1985 as an add-on to MS-DOS in response to the growing interest in graphical user interfaces . Microsoft Windows came to dominate the world's personal...
-based software. This license is not open source, as defined by the OSI
Open Source Initiative
The Open Source Initiative is an organization dedicated to promoting open source software.The organization was founded in February 1998, by Bruce Perens and Eric S. Raymond, prompted by Netscape Communications Corporation publishing the source code for its flagship Netscape Communicator product...
, because the restriction limiting use of the software to Windows violates the stipulation that open-source licenses must be technology-neutral. It is also considered to be non-free by the Free Software Foundation due to this restriction.
Microsoft Limited Reciprocal License (Ms-LRL)
This is a version of the Microsoft Reciprocal License in which rights are only granted when developing software for a Microsoft Windows platform. Like the Ms-LPL, this license is not open source because it is not technology-neutral due to its restriction that licensed software must be used on Windows, and is also non-free due to this restriction.Non-free licenses
The following projects are under a Shared source license, but are neither free softwareFree software
Free software, software libre or libre software is software that can be used, studied, and modified without restriction, and which can be copied and redistributed in modified or unmodified form either without restriction, or with restrictions that only ensure that further recipients can also do...
according to the Free Software Foundation
Free Software Foundation
The Free Software Foundation is a non-profit corporation founded by Richard Stallman on 4 October 1985 to support the free software movement, a copyleft-based movement which aims to promote the universal freedom to create, distribute and modify computer software...
, nor OSI
Open Source Initiative
The Open Source Initiative is an organization dedicated to promoting open source software.The organization was founded in February 1998, by Bruce Perens and Eric S. Raymond, prompted by Netscape Communications Corporation publishing the source code for its flagship Netscape Communicator product...
-approved open source
Open source
The term open source describes practices in production and development that promote access to the end product's source materials. Some consider open source a philosophy, others consider it a pragmatic methodology...
.
Microsoft Enterprise Source Licensing Program
Microsoft gives enterprise customers viewing access to some parts of some versions of the Microsoft Windows
Microsoft Windows
Microsoft Windows is a series of operating systems produced by Microsoft.Microsoft introduced an operating environment named Windows on November 20, 1985 as an add-on to MS-DOS in response to the growing interest in graphical user interfaces . Microsoft Windows came to dominate the world's personal...
operating system
Operating system
An operating system is a set of programs that manage computer hardware resources and provide common services for application software. The operating system is the most important type of system software in a computer system...
s. The ESLP license agreement is among the most restrictive of the licenses associated with Shared Source programs, allowing no modifications of the code.
Microsoft Windows Academic Program
The Windows Academic Program provides universities worldwide with concepts, Windows kernel source code, and projects useful for integrating core Windows kernel technologies into teaching and research.
Microsoft Government Security Program
The Microsoft Government Security Program is an effort to assist national governments in evaluating the security of Windows and of other Microsoft products. Participating governments have access to the source code for current versions of Windows and Windows service packs, Windows Embedded CE, and Microsoft Office.
Most Valuable Professionals Source Licensing Program
Through this program, Microsoft makes Windows source code available to members of their "Most Valuable Professional"
Microsoft Most Valuable Professional
The Microsoft Most Valuable Professional is the highest award given by Microsoft to those it considers "the best and brightest from technology communities around the world" who "actively share their ... technical expertise with the community and with Microsoft"...
program. MVPs are members of the developer and support community who have made significant public, volunteer contributions, primarily through participation in online forums. The MVP Source Licensing Program allows licensees to use the source code for debugging and support purposes, though it may not be used to aid in the development of a commercial product.
Microsoft Shared Source Common Language Infrastructure
The first widely-distributed Shared Source program was Shared Source CLI
Shared Source Common Language Infrastructure
The Shared Source Common Language Infrastructure , previously codenamed Rotor, is Microsoft's shared source implementation of the CLI, the core of .NET. Although the SSCLI is not suitable for commercial use due to its license, it does make it possible for programmers to examine the implementation...
, the Shared Source implementation of the Common Language Infrastructure
Common Language Infrastructure
The Common Language Infrastructure is an open specification developed by Microsoft and standardized by ISO and ECMA that describes the executable code and runtime environment that form the core of the Microsoft .NET Framework and the free and open source implementations Mono and Portable.NET...
. The licensing permits non-commercial modification and distribution of the source code, as long as all distributions include the original license, or one encompassing the original terms.
Free licenses
The following projects are under a specific Shared source license which is considered free softwareFree software
Free software, software libre or libre software is software that can be used, studied, and modified without restriction, and which can be copied and redistributed in modified or unmodified form either without restriction, or with restrictions that only ensure that further recipients can also do...
according to the Free Software Foundation
Free Software Foundation
The Free Software Foundation is a non-profit corporation founded by Richard Stallman on 4 October 1985 to support the free software movement, a copyleft-based movement which aims to promote the universal freedom to create, distribute and modify computer software...
and the Open Source Initiative
Open Source Initiative
The Open Source Initiative is an organization dedicated to promoting open source software.The organization was founded in February 1998, by Bruce Perens and Eric S. Raymond, prompted by Netscape Communications Corporation publishing the source code for its flagship Netscape Communicator product...
.
ASP.Net AJAX Control Toolkit
The ASP.NET AJAX Control Toolkit is a set of controls and extenders that use AJAX technologies to enable developers to improve the client experience on their web sites. The toolkit is licensed under the Microsoft Public license (MS-PL) and is available on CodePlex, Microsoft’s online community development portal for collaborative software development projects.