Re: License compatibility of MS-PL and MS-CL (Was: (RE: Groklaw's OSI item (was: When will CPAL act

John Cowan wrote:

> I sincerely hope that these reassurances will dispose
of all bogus
> incompatible-with-everything claims, though I know this
list far too
> well to suppose that we will actually hear no more of
them.

He said that binary derivative works containing MS-PL code
could be
under any license.  I'm concerned about derivative works
distributed as
source code.

The only thing he said about this is "The purpose of
requiring
that source code redistributions be made only under the
terms of the
Ms-PL is to allow developers a choice of a license that will
ensure that
their source code will only be distributed under terms that
they have
explicitly chosen. [...] The Ms-PL provides developers a
licensing
option that ensures their code will be distributed initially
and later
under terms and conditions they have chosen and agree
with."

Matt Flaschen

tor, 23.08.2007 kl. 16.48 -0400, skrev Matthew Flaschen:
> The only thing he said about this is "The purpose
of requiring
> that source code redistributions be made only under the
terms of the
> Ms-PL is to allow developers a choice of a license that
will ensure
> that
> their source code will only be distributed under terms
that they have
> explicitly chosen. [...] The Ms-PL provides developers
a licensing
> option that ensures their code will be distributed
initially and later
> under terms and conditions they have chosen and agree
with."

I find it quite informative. Someone who releases source
code under the
BSDL may later find the code distributed under just about
any terms and
conditions. If the purpose is for the MS-PL to behave in a
similar way
in that respect, then the above statement would not make
sense.

Note that he does not state that the purpose is to prevent
code
initially released under different terms and conditions from
later being
distributed under the MS-PL.

Nils Labugt

On Thu, 23 Aug 2007, Matthew Flaschen wrote:

> John Cowan wrote:
>
>> I sincerely hope that these reassurances will
dispose of all bogus
>> incompatible-with-everything claims, though I know
this list far too
>> well to suppose that we will actually hear no more
of them.
>
> He said that binary derivative works containing MS-PL
code could be
> under any license.  I'm concerned about derivative
works distributed as
> source code.

First, let me echo others' thanks to Mr. Thatcher for his
analysis of the 
binary distribution case, and hope that he will also be able
to shed some 
clarifying light on the source distribution case.


Having said that, Jon Rosenberg (the Microsoft rep who
posted the MS-PL 
for consideration here) also posted a small FAQ at that time
which 
answered the question fairly clearly:

"* Can MS-PL code be redistributed under a different
license?:
No.  The license states that "If you distribute any
portion of the 
software in source code form, you may do so only under this
license..." 
This restriction is similar to the restriction in the
Mozilla Public 
License that states "You may not offer or impose any
terms on any Source 
Code version that alters or restricts the applicable version
of this 
License or the recipients' rights hereunder."  The
MS-PL license 
explicitly prohibits relicensing of the original licensed
code under a 
different license, regardless of whether the original code
is 
redistributed in whole, in part or as part of a different
piece of 
software."


In particular:

"...regardless of whether the original code is
redistributed...as part of 
a different piece of software."


John Cowen points out that derivative works are allowed, but
2(A) says 
they are "Subject to the terms of this license,
including the license 
conditions and limitations in section 3." Thus
derivative works are NOT 
allowed if they violate section 3, which says "If you
distribute any 
portion of the software in source code form, you may do so
only under this 
license..." The FAQ answer reinforces the fact that
distribution of "any 
portion" includes when part of a derivative work (a
"different piece of 
software").


Chris Fagan (also of Microsoft) repeated the basic idea of
this more 
recently in a post here:

"Our intention in designing the MS-PL is most clearly
understood by 
thinking about how a developer may want to make source code
they developed 
available to their users (i.e. other developers etc).  A
design goal of 
the MS-PL is to allow developers to choose to ensure that
the specific 
rights in Section (2) continue to be available to downstream
developers 
and users through generations of adoption and
adaptation."


In particular:

"...to ensure that the specific rights in Section (2)
continue to be 
available to downstream developers..."

That certainly suggests that you cannot place any additional
restrictions 
downstream of MS-PL code. Since you rather obviously cannot
place FEWER 
restrictions on it, your only option is to place identical
restrictions 
(ie, using the MS-PL).


So lines of source code released under only MS-PL by their
original author 
can never find themselves under another license by any means
(though their 
compiled binary representation can). Attempting to create a
derivative 
work that places those lines of code under another license
(when they are 
within the derivative work) violates section 3(D) and thus
violates your 
license to create said derivative work.


Whether there is some clever way to legally keep pure MS-PL
code distinct 
from pure BSDL code in a project that generates a single
executable is 
perhaps a more complicated legal question (though linking is
certainly 
valid). However, requiring a technical restriction of
keeping the code 
distinct (often an impossible restriction depending on your
needs) is 
probably not what one would call "compatible". I
pity any developer who 
would saddle their fledgling open-source project with such a
burden.

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physics will always be
Software Engineer                     safer than biology,
for while the
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