Please be patient. See demos.htm . The garbage collector interferes with smooth performance. After Hugs and GHC are merged, this problem should not be noticeable. As of very recently, Fran works with GHC .
Performance is much better.
Installation is somewhat painful, but that situation is improving. If you're interested, see HowToGHC.txt . Well, there are a few missing pieces, related to GreenCard, so you'd better wait. Try examples of your own. Then try it out.