[coldtea]

Haven't seem them getting slower in later stages, and surely not THAT slower. Any citations?

Their main problem is that the project got mostly abandoned in favor of the paid-for RubyMotion (which uses AOT compilation).

That said, Lua and JS are as dynamic and Ruby and both are plenty faster.

And PyPy is plenty faster than Python, despite being 100% compatible now.

[Argorak]

Yes, but PyPy was not written in 6 months. For a rather comprehensive (but not so recent) benchmark, see:

http://etehtsea.me/the-great-ruby-shootout http://igor-alexandrov.github.io/blog/2012/11/05/yet-another...

MacRuby looses against MRI in many benchmarks and MRI doesn't fare as bad as many people say.

[kingkilr]

PyPy wasn't, but as a result of the groundwork we laid in building it, I (and several contributers) were able to build Topaz in under a year: http://topazruby.com/

[Argorak]

How much work do you expect it to be capable to replace MRI?