GitHub is basically the world’s code repository. Microsoft own it, and one can see this as a big commitment to Open Source. But GitHub is also and foremost a specialized and extremely qualitative social network. Coupled with Linkedin (same : specialized and qualitative), that makes two highly qualitative social network for Microsoft. You can’t really say if Linkedin could empower Github or is it the other way. Add some clever ML on top of all that data, and Microsoft have gold between their hands.