Interesting, I had thought OCaml and Haskell were pretty equivalent in regards to functional programming. OCaml's plus is the ability to break out of the functional mindset when you really need it, mainly for speed (can beat c++ when used properly): http://www.cs.ubc.ca/~murphyk/Software/Ocaml/why_ocaml.html

I think that is cool, because in my mind functional and imperative programming each have their distinct niche's of effectiveness. However, I have zero significant projects under my belt in any functional language, so I'm not necessarily one to talk.

Update

This is a counter (on slashdot w/ discussion) to the speed claim: http://developers.slashdot.org/article.pl?sid=05/03/14/22582...