I'm sure that also plays into it. Though DefinitelyTyped was started by someone who AFAIK is unaffiliated with MS, and I would say that is pretty critical to it

I'm sure that also plays into it. Though DefinitelyTyped was started by someone who AFAIK is unaffiliated with MS, and I would say that is pretty critical to its success. I should have specified that the above is the reason I would choose TypeScript over Haxe now. There's a lot of times when I will prototype a project in vanilla JavaScript, then set up the TypeScript build infrastructure and start enhancing.