BSD and MIT license "compliance" with the MS-PL

saulgoode at saulgoode at
Fri Apr 17 09:51:05 UTC 2009

Thank you for your response. Your assessment (as I understand it)  
tends to reinforce my understanding of the paradoxical nature of the  
MS-PL as an open source license; i.e., it incentivizes closed-source  

Quoting Donovan Hawkins <hawkins at>:

> On Wed, 15 Apr 2009, saulgoode at wrote:
> The "complies with" clause was for binary distribution only, so you
> wouldn't be using any open source license there. Your closed-source
> license only needs to contain the restrictions of the MS-PL (such as
> the patent claim termination and disclaimer) can pick and choose
> what rights you pass along.

This is the cause for my concern. If a collaborative project  
incorporates some MIT-licensed code then even in the case of releasing  
binaries, unless the project is the copyright holder for the entirety  
of that MIT-licensed codebase (or other arrangements have been made  
with all copyright holders of contributions), it is not empowered to  
terminate any patent claims inhered in that code. Without offering a  
patent grant for code contributed by all project collaborators, the  
project can't "comply with" the MS-PL and meet its requirements.

> Footnote: If you are a developer who thinks of open source as raw
> material to use in your closed source software, the MS-PL *does* fit
> what you think of as open source quite nicely.

It would seem that the MS-PL is not even a good choice for  
closed-source software, if projects -- regardless whether their  
releases are open or closed -- can't leverage the abundance of  
BSD-licensed and MIT-licensed code available.

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