For Approval: Microsoft Permissive License

Nils Labugt elabu at
Sat Aug 18 21:50:56 UTC 2007

lør, 18.08.2007 kl. 10.43 -0700, skrev Michael R. Bernstein:
> From my POV, the fundamental difference here is *how* they choose to
> exclude. Other pairwise license incompatibilities (including those that
> involve the GPL) arise out of the side-effects of incompatible terms (in
> the GPL's case, 'no other restrictions'), which at least leaves the door
> open for pairwise combinations that are compatible.
> In contrast, the MS-PL and MS-CL, by virtue of explicitly excluding
> other licenses wholesale (including each other!), seem to have license
> incompatibility as a *design goal* rather than a side-effect, and it is
> *that* which I am very uncomfortable with. 

For comparison, first from MS-PL: 

"(D) If you distribute any portion of the software in source code form,
you may do so only under this license by including a complete copy of
this license with your distribution."

>From CPLv1:

"When the Program is made available in source code form:

a) it must be made available under this Agreement; and
b) a copy of this Agreement must be included with each copy of the

>From GPLv3:

"5. ...
b) The work must carry prominent notices stating that it is
   released under this License and any conditions added under section
   7. [...]

c) You must license the entire work, as a whole, under this
   License to anyone who comes into possession of a copy.  This
   License will therefore apply, along with any applicable section 7
   additional terms, to the whole of the work, and all its parts,
   regardless of how they are packaged.  This License gives no
   permission to license the work in any other way, but it does not
   invalidate such permission if you have separately received it."

"4. ...and give all recipients a copy of this License along with the

Comparing these excerpts, I don't see why it is a "design goal" in the
case of the MS-PL but only a side-effect in the other two cases.

> Not to mention eliminating
> the possibility of dual licensing.

If the license file and every source file states in no uncertain terms
that the program is dual licensed, then I would be surprised if a judge
lets the language "only under this license" in the MS-PL override that.

Nils Labugt

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