I seem to hear so much on HN about most of the other "popular" FP languages, but haven't heard much about OCaml lately. Haskell, Clojure, Scala, CL, Scheme, etc. all get their due, but OCaml has always been my choice.
Here's one place you might be surprised to see it in action: <a href="http://www.janestcapital.com/technology/ocaml.php" rel="nofollow">http://www.janestcapital.com/technology/ocaml.php</a>