What does Microsoft's new shared source mean for you?

Out-Law Analysis | 20 Oct 2005 | 5:08 pm | 2 min. read

Analysis: Open source advocates are doing what was once unthinkable giving the thumbs up to a Microsoft source code licensing program.

By Gavin Clarke in San Francisco for The Register

This article has been reproduced from The Register, with permission.

The Free Software Foundation has said new licenses for Microsoft's pseudo open source program, the Shared Source Initiative, appears to satisfy the four requirements defining Free Software. Professors Larry Lessig and Ronald Mann, meanwhile, welcomed Microsoft's changes saying they reduce the number of open source licenses in use by the community.

In fact, there are five more, as of today.

This early support is a sharp contrast to the criticism levelled by the open source movement at Sun Microsystems when it launched its Common Development and Distribution License (CDDL), to cover the release of Solaris and its middleware.

While any improvement to Microsoft's Kafka-esque source licensing will be welcomed by developers and enterprises, this latest set of options represents a continued, if somewhat predictably limited, evolution in Shared Source.

Permissive Society

Microsoft has introduced three top-level licenses, which dictate the terms and conditions under which code for Microsoft technologies are released through Shared Source. The three are Microsoft Permissive License (Ms-PL), the Community License (Ms-CL) and the Reference License (Ms-RL).

It's there that things start to get a bit more complicated.

Microsoft is also introducing two sub-licenses, Limited Permissive License (Ms-LPL) and Limited Community License (Ms-LCL) that's complication enough. However, Microsoft is adding another layer, as the five licenses only apply to new code released under Shared Source; it is unclear probably unlikely that more than 80 Microsoft technologies already available under Shared Source will be ported to the new licenses.

Additionally, the open source-friendly noises made by Microsoft appear to be just that noises. Ms-LPL and Ms-LCL restrict the use of Shared Source code to Windows. Code released under these sub-licenses will not, for example, find its way onto Linux.

Furthermore, the big-ticket items like Windows and Office available under Shared Source for government are unlikely to be re-released under the new licenses. A Microsoft spokeswoman told The Register this would be a decision for the individual technology groups.

Instead, Microsoft is aiming relatively low on what it releases. The spokeswoman said Microsoft's Bluetooth wrapper for Windows CE and eight starter kits for Visual Studio 2005 will be released under Ms-PL. The latter, for example, to add the ability for applications to keep track of new film releases on Amazon.com.

That's a continuation of existing policy. Microsoft released its Windows Template Library, Windows Installer XML and FlexWiki to SourceForge to SourceForge last year.

There is an upside. Ms-PL allows developers to view, modify and redistribute source code for commercial and non-commercial without paying Microsoft royalties. Ms-CL stipulates that where Ms-CL is used in a particular file then the entire file must be re-distributed in source code form with a "per-file reciprocal term".


Microsoft is clearly taking something of a"copy left" approach to Shared Source, an approach that is used widely in the real open source community.

Microsoft is notoriously obsessed with detail when it comes to licensing.

The shenanigans around Microsoft Communications Protocol Program (MCPP) proved it was more than happy to release code while putting up just enough bureaucratic hurdles to make obtaining that code by developers too complicated and time-consuming for them to bother.

These latest changes should be seen in this context and will come as little surprise when you remember how Shared Source started life: as a response to increased concerns among customers to the security of its products in light of numerous worm attacks, and the growing success of open source and Linux, particularly in the government sector.

The five licenses represent another shift in Microsoft's journey closer to the open source community and development methodologies. While welcome, the changes give the community just enough of what it wants while leaving Microsoft in the driving seat in terms of what code it releases and the conditions it uses.

© The Register 2005