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

[Tzeng, Nigel H.]

>From: Matthew Flaschen [matthew.flaschen at gatech.edu]
>>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.