For those interested in contributing to the F# language itself and the compiler, the F# Open Engineering Group has an article on that topic <a href="http://fsharp.github.io/2014/06/18/fsharp-contributions.html" rel="nofollow">http://fsharp.github.io/2014/06/18/fsharp-contributions.html</a>
Just Microsoft's rebrand and restricted version of OCaml. And, imho, it is much better to use original language (since it have much more features), especially with Core library.