This is exactly my worry.

1. Embrace Git by buying Github

2. Extend Git, fork git to add Github specific features (Basically integrate https://hub.github.com/ directly into git)

3. Extinguish, by gradually making Github incompatible with the original git. Then stop development on the forked git and push everyone to a proprietary product.

This is complete nonsense. Microsoft has actually _contributed_ to Git. But even outside of that Azure makes them a metric fuck ton of money. They need developer support to continue using Azure which also means Git integration.

They are not going to slowly change git to the point where no one else can use it. Git is opened sourced, by owning GitHub they still can't control Git anyway.

When I left MS about 4 years ago they were working on switching their internal source control over to Git. Not sure on their progress, but that hardly seems like they'd make it incompatible.

Exactly, there are a few MSDN/Channel 9 articles describing the pains of pulling the Windows repo into Git. If anything, Microsoft is going to make Github, and Git, much better. They have the largest code bases in the world, they aren't going to change anything that will disrupt internal processes, but will build tools to help others with massive codebases live better in Github.

I also don't see it - but isn't making Git 'much better' essentially extending it? If they released some kind of tight integration that was actually really useful and only worked well in the github context, don't you think people would use it? I can't imagine what form such a thing would take, but it definitely seems possible.