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

Tzeng, Nigel H. Nigel.Tzeng at
Sun Apr 19 01:15:44 UTC 2009

>From: Matthew Flaschen [matthew.flaschen at]
>>Tzeng, Nigel H. wrote:

>> Given that the MS-PL is an open source license (OSI) and a free
>> software license (FSF) and it's viral  it's hard to argue that it
>> doesn't preserve source availability and therefore doesn't qualify as
>> a weak copyleft.

>Actually, it's quite easy to argue that it doesn't preserve source
>availability.  A distributes alpha version of Foo under MS-PL.  B makes
>FooBar derivative, which becomes fanatically popular, and no version of
>FooBar's source is ever released.  Source availability is denied for
>almost every user of a Foo derivative.

This is the equivalent of saying that BSD is not an open source license because Foo is BSD and no version of FooBar's source is ever released.

More information about the License-discuss mailing list