0.9rc * Efficient AVL-tree based implementations of Set and Map (Adrian Hey) * efficient conversion routines between those Sets and Maps * class-based Collection framework for abstracting over Collections, Sequences, Maps, Sets. * QuickCheck-based validation of the instances. * Benchmark suite * Adaptation of Ross Paterson's Foldable class to MPTC+FD. * Trie data type, to map sequential types (eg. lists) to keys. * new function that generalizes insertion/deletion/update in a map. > alter :: (Maybe a -> Maybe a) -> k -> Map k a -> Map k a (also added to legacy Map/Set) * Efficient Set type for enumerations. (David F. Place)