Just found out about this today, of all places from the OpenSolaris ZFS discussion list. Haskell User's Operating System and Environment. Very neat! I haven't tried it yet but the idea of being able to implement an OS in a pure functional language is pretty cool. Hmn now how cool would it be if this could be done on SPARC with the new UltraSPARC T1 - no I'm not going to do the port, I've got too much other stuff to do. Bet they could do with having DTrace for Haskell :-)