Most "competing" projects are not friendly: marketing materials put out deride the alternative as "slow", "buggy", or what-have-you (some of the stuff put out about my project simply makes me want to quit it is so nasty).

Interesting, then, that, for whatever reason, I do /not/ see this kind of behavior with the various Ruby implementations: most people I deal with in that community actually seem to enjoy the various versions existing and work together. In this case, I wouldn't even call it "competition": I'd call it "cooperative experimentation".

But this argument breaks down when you look at the nginx vs. Apache example: proponents of nginx tend to just pummel Apache with pain, even when many of the claims aren't even true (which is extra stupid as I don't even think it is correct to believe that nginx and Apache are trying to solve the same problem).