I think reasonable people can probably agree that there is a difference in kind between CoffeeScript and TypeScript. CoffeeScript was functionally equivalent to JavaScript, whereas TypeScript has feature-level improvements that are worth a developer's time. Sure, TypeScript is pushed by Microsoft. It's also an excellent solution for large-scale systems, its adoption is nontrivial, and Microsoft has a history of supporting its tools (Managed C++ aside, I suppose) in a way that can offer a promise of consistency on its own.