DARCS is an Acronym for David's Advanced Revision Control System. It is a simple to learn and use replacement for CVS with a powerful new approach to meet the needs of today's distributed software projects: it is decentralized and based on a "theory of patches" with roots in quantum mechanics.
Perhaps one of the more interesting aspects of DARCS is that it is a large-scale application written in Haskell — a rare beast.
One page links to DARCS: