Becoming Productive in Haskell
I don't think I have ever used a haskell program written by someone else that wasn't ghc. Is that usual? Are there now a bunch of .debs for useful things other than writing haskell that are actually written in Haskell? 
I'm not trolling, it's just a good test of what something is useful for when it's been around a while is to ask "Well, what has it actually been used for?"