With an emphasis on "mostly". The intent seems to be that Microsoft don't want their Redistributable Components made avaiable under the GPL or a GPL-like license, which is fair enough, really. The bit about "for use only under a Microsoft OS" could be argued that they don't want to have support problems with them under a non-Microsoft OS, which is also fair enough, except that it could be read that they don't really want their API being implemented in a non-Microsoft OS... :-)

I don't like the bit about "under an EULA". That's pushing it a bit far, IMHO. Is this targetting code built on MS's sample code? Or any code using the SDK? I suspect the former, but I also suspect many people will think they mean the latter.

IANAL.

Wade.