Legend has it there is a small room at FBHQ, containing a quorum of OCaml committers, all of them French for some reason, hacking away at level of abstraction beyond the ken of mortal man.
That's not a legend, it's true since they're doing a partnership with INRIA where OCaml was born. Those French computer scientists know something that American companies don't and that's that theory is important as an underlying foundation for extraordinary results.
I'd actually expand that to European - in my grad studies, the European CS world had a much more mathematical bent. Notice the the Glasgow Haskell Compiler, Coq, etc.
You can always go from math -> pragmatism, but the reverse is nearly impossible. People get set in their ways, and it takes time to develop mathematical rigor, even if you want to.
So when you need to get mathematical expertise, you wind up needing to hire it.
A pretty sizable chunk of the OCaml world is French. It was developed at INRIA, yeah, and maintains a lot of presence there. It's actually a tiny bit difficult from time to time in OCaml to find English resources.
