Hi, After discussions with Malcolm, there are a number of things that need to be done before Yhc can replace nhc: 1) Performance: Yhc must perform faster than nhc, we used to, but we don't anymore. Tom is going to investigate. 2) Buildability: Malcolm still can't build on his Mac, due to library issues. Tom is going to remove all dependencies on all libraries, which should enable this. Even so, we need some work on the build system to get the libraries working for him. I think Malcom is the only person who has build system problems, so perhaps we can fix this for him. 3) Libraries: We need to move to the Haskell.org libraries. This may mean increasing our build stuff, or moving to Cabal. 4) Compatability: We need to compile more programs than nhc, this probably comes down to primitives and libraries. 5) Bootstrapping: We need to bootstrap Yhc with itself. Moving to one nhc/Yhc derivative is clearly a good thing. If anyone wants to take on any of these tasks, or has insights into how we can do this more quickly, we'd love to hear! Thanks Neil