License proliferation in the open source community is a much-debated and
hotly contested topic.
Microsoft, a company often reviled in the open
source community, has taken dramatic steps to simplify its open source style
shared source licenses by paring the number it offers down to three.
Microsoft established its Shared Source Initiative in 2001 and had been
offering over 10 licenses under which code could be shared. There are currently more than 80 Microsoft technologies available via shared source and over 600 non-Microsoft technologies released under one of the many shared source licenses.
As of today, Shared Source Initiative technologies will be simplified under a new three-license regimen, which includes The Permissive License (Ms-PL), The Community License (Ms-CL) and the Reference License (Ms-RL).
The Ms-PL allows users to view, modify and
redistribute source code for non-commercial and/or commercial purposes. It
also allows a developer to actually charge a licensing fee for modified code
based on an Ms-PL-licensed application.
Microsoft announced today that eight new Visual Studio 2005 starter kits
and the next Windows CE Bluetooth Wrapper would be offered under the Ms-PL.
The Ms-CL is reciprocal, which means a
developer who redistributes code needs to license it under the
same terms. A reciprocal license also usually means that the developer is
obliged to commit any changes made to the code back to the project under the
Modification and redistribution for commercial and non-commercial
use is allowed under the terms of the Ms-CL.
The Ms-RL is for reference only. Modification and
redistribution of code licensed under the Ms-RL are not allowed.
Jason Matusow, the director of Microsoft’s Shared Source Initiative wrote on his blog that the proliferation of source code licenses had become problematic.
In his view, as increasing numbers of developers were going to
be using shared source initiative code, he wrote, the number of licenses could have grown to even more than the 10 plus that Microsoft was already using.
“Today, Microsoft is simplifying its source code licensing so that
developers working with our technologies will be able to focus on developing
great software rather than understanding a license,” Matusow wrote. “Our source code licensing needs to be simple and predictable. [Three] is better than more than 10.”