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

Donovan Hawkins hawkins at
Sun Apr 19 07:04:48 UTC 2009

On Sat, 18 Apr 2009, Tzeng, Nigel H. wrote:

> You're essentially asking why anyone would want to do permissive 
> licenses.  Because some of us don't really care if folks use the code in 
> closed source.  We write code to scratch our own itch and hope it's 
> useful for someone else.

Your argument would work if the MS-PL were actually permissive, but it 
seems you are using the same definition that Microsoft used when they 
first named the license (one which they fortunately corrected during 
license discussion). Permissive does not mean "usable by closed 
source"...that is merely a side affect.

A permissive license allows reuse under a license of the downstream 
developer's own choice. You can do pretty much anything you want with the 
code as long as you don't sue the original author or deny him credit for 
the work. The philosophy behind permissive licensing need not be 
maintained by downstream licenses.

A reciprocal license allows reuse only under the same license as the 
original. It is created as a defense for a particular philosophy, and all 
downstream licensing will preserve it.

The MS-PL restricts downstream licensing in order to prevent people from 
GPL-ing the code and locking out closed source. The GPL similarly 
restricts downstream licensing in order to prevent people from 
closed-sourcing the code and locking out open source. Both licenses have 
an agenda, both licenses enforce that agenda with licensing restrictions, 
so neither license is permissive.

> A copyleft license enforces this courtesy.  A permissive license allows 
> reuse in closed source projects.

Either you want to control the restrictions that people place on 
downstream code or you do not. If you do, then the license that 
accomplishes it is not permissive. The fact that the MS-PL only wants to 
place restrictions on how open source developers use the code does not 
change the fact that it places restrictions, though it does explain why 
open source developers are unlikely to use it.

> No, I say your definition of open source is narrow because you believe 
> that no one using MS-PL is doing open source.

People are free to use whatever license they wish on code they write, but 
I am also free to question their sincerity if they use MS-PL and think it 
makes sense as an open source license. Objections to the way GPL locks out 
closed source seem hollow if made by people who lock out GPL using the 
exact same mechanism in order to protect the rights of closed source 
projects which lock out everyone.

> However a GPL fork will take your code and potentially can take your 
> community (your dev base) and create a new commons based on your work 
> that you can't reuse without adopting their ideology.

An interesting practical application of the MS-PL in open source, though I 
find it ironic that a person who dislikes this aspect of the GPL would 
choose a license which does exactly the same thing. He discarded the 
principle to protect himself.

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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