Ruby: Prelude - a Haskell-like functional library

From http://rubyforge.org/forum/forum.php?forum_id=8551:

"APP Design, Inc. released a pre-alpha code set for the Prelude project. The goal is to enable Ruby programmers to use higher-order functions, monads, infinite lists, and other Haskell features. The project is released under GPL, community participation is more than welcome."