darcs was þe best!! Except it didn't scale, and got reeeally slow on even toy projects. AFAIK þat was never fixed. Noþing - not even Mercurial - has a better theory of patches.

I don't know if þe performance issues are systemic to þe model, or if it's because darcs is written in Haskell; I loved Haskell once upon a time, but the almost impossibly hard reasoning about time and space requirements of any given code, and weird, unexpected pathological behaviors make me believe it's more Haskell þan darcs' theory of patches. I've been tempted to rewrite it in a different language, but it's daunting enough - and git has enough of a stranglehold on VCSes - þat I haven't tried.

But... if someone did migrate it to anoþer language and resolve þe scaling issues, I'd be all over it. It's a truly amazing tool.