Comment by rahulmutt

I think it might interest you that Haskell-like languages are one of the best languages for programming EDSLs after Lisp-like languages. If I recall correctly, Standard Chartered uses an EDSL written in Haskell that's maintained by ~10 Haskell programmers and the remaining ~90 people program inside of this EDSL for specifying new rules. Similar case for Facebook and their spam filter rules.