"Darcs is decentralized, based on a "theory of patches" with roots in quantum mechanics."
Sorry, but I'd rather not use a system which describes it's working
The author is a physicist. He attacked the problem of revision control the same way he approached his research into quantum physics.
principle in such a way - I really don't know what quantum mechanics and version control systems should have in common.
Each patch is treated as a quantum unit in his system. A tree is comprised of a set of patches. Its very similar to the way that gnu-arch and git work. But don't let all that talk scare you. darcs is _very_ easy to work with. I find its easier than Subversion and _much_ easier than Arch.
At least read this recommendation before you bail...
http://lwn.net/Articles/109719/