Probabilistic Functional Programming
From HaskellWiki
Probabilistic functional programming is a library for discrete random variables in terms of their distribution. Examples include dice games, the Monty Hall paradoxon and others.
 Erwig and Kollmansberger: Probabilistic Functional Programming
 http://eecs.oregonstate.edu/~erwig/pfp/
Version maintained by Henning Thielemann:
 http://hackage.haskell.org/cgibin/hackagescripts/package/probability

darcs get http://darcs.haskell.org/probability/