Following discussions a while back: http://www.haskell.org//pipermail/libraries/2006-January/004815.html there was some concensus (although not unanimous) that Cabal's user interface should be a wrapper program that runs Setup.hs. I've implemented a first cut at this, see the attached Cabal patch. It addresses this ticket: http://hackage.haskell.org/trac/hackage/ticket/63 I'm sending it here rather than committing directly, because I imagine there will be some discussion about whether this is the right thing. I'm pretty convinced this is the right way to go: it solves the Cabal versioning problem, and it frees the programmer from having to write a boilerplate Setup.hs file. It's a step on the way to supporting building of multiple packages. Look at the patch, tell me what you think. You'll need a completely up-to-date Cabal from darcs to build it. Cheers, Simon