I would like to have several versions of ghc installed simultaneously, on the handful of Ubuntu systems I work on. In the past, I have had just a single version of ghc installed on each system, usually the most recent stable generic Linux binary installation. Three questions: 1. Does there exist an `experimental' apt repository for Ubuntu anywhere which packages versions of ghc more recent than 6.8? 2. If I cannot install multiple ghc versions from a different apt repository, does anyone have advice for how to work with multiple simultaneous installations? A how-to guide or anything like that? 3. Does having multiple installations break cabal at all? I'd like to be able to use ghc 6.12.* by default, but be able to selectively choose an older toolchain for compatibility purposes, bug hunting, etc. Thanks! Sincerely, Brad