Generalized newtype deriving is introduced.Generalised derived instances for newtypes in GHC 5.04 This feature will become the
GeneralizedNewtypeDeriving extension in GHC 6.6.
This is the first GHC version in which the package name
basebase in GHC 5.04 appears. It contains standard library that previously existed in the package called
base package does not yet have a version number; package version numbers will not appear until GHC 6.4.