[dalke]

At this point it's conjectural if this implementation Ruby will get there. The headline implies that it's already the case. Hence it's a misleading headline.

We know that an implementation of Python can be faster than equivalent code in C, as in the carefully crafted examples of http://morepypy.blogspot.com/2011/08/pypy-is-faster-than-c-a... or http://morepypy.blogspot.com/2011/02/pypy-faster-than-c-on-c... .

It should therefore not be surprising that for carefully crafted benchmarks and with enough time and effort, a Ruby implementation can be as fast as the equivalent Java code. But history is littered with the corpses of implementations that tried and failed to meet its performance goals. (Python's Unladen Swallow being but one example.)