Apart from using suboptimal Lua code (the author obviously doesn't know about the Lua keyword 'local'), LuaJIT beta2 didn't compile recursion at all. It runs more than 4x faster with the current version and beats MacRuby easily.
Oh, and comparing language implementations based on the speed of a recursive Fibonacci number generator has exactly zero real-world relevance. Try again with a more realistic mix of benchmarks or something domain-specific like SciMark (LuaJIT is only 30% slower than GCC on this one).
Judging from http://antoniocangiano.com/2010/05/16/benchmarking-macruby-0... MacRuby plays in the same league as the other Ruby implementations. And http://shootout.alioth.debian.org/u32/benchmark.php?test=all... tells you where that league can be found, relative to LuaJIT. Hint: scroll to the bottom. :-)