License compatibility of MS-PL and MS-CL (Was: (RE: Groklaw's OSI item (was: When will CPAL actually be _used_?))

Michael R. Bernstein michael at
Thu Aug 23 17:10:24 UTC 2007

On Thu, 2007-08-23 at 08:54 -0400, John Cowan wrote:
> Michael R. Bernstein scripsit:
> > No, let me amend that: It bothers me that these licenses are
> > incompatible with the entire universe of all other theoretically
> > possible licenses, including future ones, regardless of their terms.
> What you say is not *false*, technically, but it's highly misleading.
> It is true that you can't take code licensed under the MS-PL and place
> any other license on it directly.  However, it is still possible to make
> a derivative work that incorporates MS-PL licensed code (by clause 2A).
> Since you are the copyright owner of this derivative work, you may license
> it under any terms you like that do not actually contradict the terms of
> the MS-PL; that lets out the GPLv2 because of the patent peace clause (3B),
> but allows many other licenses from Apache 2.0 to BSD to proprietary.

John, your position on this is based on a particular (and to me,
peculiar) interpretation of clause 3D in the MS-PL as only applying to
the original code and not derivative works distributed as source. I have
my doubts about the validity of that interpretation.

Despite your arguments to the contrary, "you may do so only under this
license" to me still means that you cannot, for example, pull *in* BSD
or other permissively licensed code and create a derivative work
distributed as source where the file as a whole is under the MS-PL but
the portion added is also under BSD.

- Michael R. Bernstein
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