I really wish there was a way to do inline optimized code, i.e a gen_server that transparently wraps another language without having to get into nif / external servers. Basically an abstraction that hides all of that cruft and builds optimized gen_servers for doing number crunching or heavy processing. Maybe I'm just being lazy. :)
I've used this, it's an awesome project, but it's basically just pipes all the way down. I'm thinking of something closer to a NIF. I think Saleyn's c++ node code might be the closest thing for a lower level language.