For Approval: Microsoft Permissive License

Donovan Hawkins hawkins at
Fri Aug 10 23:35:27 UTC 2007

On Fri, 10 Aug 2007, Jon Rosenberg (PBM) wrote:

> *         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."

(As an aside, I just noticed that both Mozilla Public License and 
Microsoft Permissive License are "MPL"...I'll use MozPL and MicroPL 

The MozPL also has an explicit statement in section 13 that permits the 
initial release under MozPL combined with another license. Both the 
MicroPL and MicroCL lack a clause like that. While I doubt the license 
agreement could prevent the original author from releasing under as many 
licenses as he chooses, it seems like a similar clause would clear up 
misunderstandings in cases where both releases come packaged together with 
a single license document (a very likely scenario).

Also, isn't the name "Permissive" rather misleading? While you are free to 
release binaries however you choose, the license is viral and the source 
code cannot be used by the vast majority (ie, any) of the existing 
open-source projects. I would hardly call that permissive...the word 
carries a lot more meaning than "non-copyleft".

Conveniently enough, changing the word "Permissive" could also clear up 
the "MPL" acronym ambiguity.

Donovan Hawkins, PhD                 "The study of physics will always be
Software Engineer                     safer than biology, for while the
hawkins at                   hazards of physics drop off as 1/r^2,                biological ones grow exponentially."

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