Good stuff!
This is part of the new Microsoft, I guess. Explicit support for Linux using gcc. Licensing is the MIT license - pretty much "do what you want".
Haven't tried compiling yet (my gcc is one version back from what they have tested, and my CPU only has AVX, not AVX2).
Still, looks like a good thing. Kudos to Microsoft!
I hope external crypto folks examine it with a fine tooth comb!