Echo JS 0.11.0

Isn't the problem they will at some point have some real or even perceived incompatibility. At this point all library writers will have to test on and customise for both projects. People are lazy so they won't do this. Then network effects take over and the bigger project wins.

Maybe I'm over simplifying. But I think that it's very hard for two very similar but slightly incompatible projects to prosper. See jenkins vs. hudson.