graydon wrote a bit on Mozilla (a project he works on) switching to Mercurial (a "competitor" VCS for Monotone, the one he created). The whole message is worth a read (in brief, he encouraged this), but this is especially quote-worthy:For whatever it's worth, I'm actually quite pleased with the result. I don't really see these systems as competing as much as co-evolving, and enabling massive increase in the rate of free software evolution. In the early 2000s, anyone I described this sort of tool to thought it was crazy and would never work. Merge *after* commit? Branches with *multiple* heads? *Content addresses* in history graphs? *No* canonical servers? Now all this is the standard, and we're quibbling over who does it fastest. Who cares? The battle is won: DVCS technology works fantastically well -- using the model we pioneered -- and free implementations of it are absorbing many major projects. That's cause for celebration.
Unfortunately, it leaves the rest of us who like to use these in a mess of quite-similar-but-incompatible systems. I tried to look at git last night (which I think of as "Linus makes monotone go faster" and has some interesting ideas about local branches) but their tutorial describes a version incompatibly newer than the one in the newest Ubuntu. (As I've written before: at this point, the docs really matter.)