I've been slow to answer this (people invited me to contribute, but I was away during this exciting week)... and so much has already been written!
All to say, I don't see how I could state it better than the Linux Foundation itself: linuxfoundation.org/blog/microsoft-buys-github-th…
I was really surprised (and disappointed) by all the negative feedback this acquisition created. It's amazing how many people are still stuck in the last decade, and haven't realized how Microsoft has changed over the last years. Microsoft is one of the biggest open-source contributors worldwide. VSCode, TypeScript, ChakraCore, have already been mentioned, but they have at least 70 engineers dedicated to contributing to Kubernetes (Azure is becoming a great cloud for k8s btw), and this is not to mention all the Kubernetes-related projects they started directly as open-source, like Helm, Draft or Brigade. Thos are awesome pieces, totally opensource. Helm just got upgraded to a Cloud Native Foundation project in the last weeks.
If you're still worried about the acquisition, or have a bad image of Microsoft related to open-source, do yourself a favor and go read that LinuxFoundation comments. Much better than any of my words ;-)