Funscript is not really MS - it's done by a third-party developer, and F# itself is open-sourced under a very liberal license, and runs well on Xamarin/Mono in OS X.
I don't think there are direct equivalents in other languages, although similar approaches exist. Checkout Elm for example:
I read about function* and yield, but this seems to require all functions to be rewritten.
Also I don't quite understand how this accomplishes to run 2 functions in parallel, if they are async.