Hello! I'd like to announce the first release of the quickcheck-instances package, which aims to consolidate commonly needed class instances for use with QuickCheck. These instances are appropriate when your tests don't have strong requirements on the nature of the input data - for example, if you are testing a network-protocol parser, the ByteString instance provided in this package might not be what you want to use. Other limitations: * I do not have full coverage of the Haskell Platform - I have been adding instances as I need them. Patches are warmly welcomed, however. * I only have instances of the 'Arbitrary' class, however I would be happy to accept patches for instances of CoArbitrary and other classes that would be useful in quickcheck-based testing. On Hackage: http://hackage.haskell.org/package/quickcheck-instances Ordinarily I frown on orphaned instances in library packages, but the fact that quickcheck properties should never appear in a library Cabal package, most of the downsides of orphans are mitigated. Thanks, Antoine