Might I suggest that you do so?
...but compared to (particularly) Lua it's just not fast enough.
I beg to differ; Here's why: http://christopherroach.com/2010/01/21/ruby-fibonacci-shooto...
I just don't like Ruby's chances when paired against the other two.
I do. JS might give it a run, with WebKit also being Apple-sponsored. But, there's no Apple-sponsored Lua implementation. And JS from WebKit doesn't have any sort of (easy to use) way to access Cocoa, like MacRuby does (with HotCocoa).