I'd like to share Michael Snoyman's Classy Prelude: http://www.yesodweb.com/blog/2012/07/classy-prelude . The basic gist of the work is that many of the standard prelude functions are made for concrete types such as [a], [(a,b)], and [Char] but can be much more polymorphic. While this complicates error messages and makes learning Haskell more difficult, we believe experienced Haskellers will benefit from the added polymorphism. Note that we aren't saying that the standard Prelude should be replaced, rather we are offering this as a drop-in alternative. Note that it reexports most of the standard Prelude types so it should be very low impact to switch over. We love to hear your comments. Note however, that this is a RFCQ with the 'C' standing for constructive.. Thanks, Max