...

From what I've seen of Clean it seems almost like Haskell. It even

distributes a Haskell->Clean translator so the obvious question is, why is Haskell slower?

It's also something I've wondered about, and I'm curious about the answer... One of the differences between Haskell and Clean is how side-effects are allowed (Uniqueness Types for Clean, and Monadic I/O for Haskell) GHC also supports a lot of extensions beyong Haskell98. Does it explain the difference in performances ? I don't know... Experts please ! Manu