Comment by bad_user

The problem of these licenses is that they don't come with patents grants. Which given that this is Microsoft we are talking about, it's a big deal.

Of course, their projects does come with a patents license, in addition to the copyright license, but it's unclear to me whether this license applies to derivative works for example. I'm not a lawyer of course and I have a very limited understanding, but interpreting their license as an English text, I really don't think it applies to derivate works. Would like an analysis of somebody knowledgeable, because a project that can't be safely forked isn't open source. Here's their license: https://github.com/dotnet/corefx/blob/master/PATENTS.TXT

Anyway, my point is that I would have preferred something like the Apache License, which is still permissive, but was written by lawyers that know what they are doing and has an explicit patents grant in it. You see, people think of BSD and MIT as being "permissive", but that's only true as far as the copyright law is concerned. Patents are a whole different thing.