Several people have reported that Hat does not compile without errors on ghc-6.4.1, and now that ghc-6.6 is available, the Hat-2.04 release certainly does not compile there either. As an interim measure, I have just made available a 'snapshot' release of Hat-2.05, specifically to ensure that it compiles with ghc-6.6. This is very much a stop-gap. There have been huge changes in the standard base library package since the last full release of Hat, which are not reflected in 2.05. (For example, Parsec and Data.FiniteMap are no longer in base, whilst Data.Map, Data.Set and so on have been added. Hat still has the older API.) The Hat team is planning to rectify these problems shortly, but we are unlikely to be able to make a full release before the end of the year. I hope the 2.05 release is sufficient to meet at least some people's needs in the meantime. Regards, Malcolm