A JIT compiled Ruby implementation in RPython

Wow, this is amazing. That PyPy was more than a fast Python implementation (closer to "a toolkit for building fast implementations of, well, pretty much anything") wasn't a big secret, but to see someone pick it up and go with it is fantastic :)

For people attending PyCon, Alex Gaynor of the PyPy team will be doing a presentation on how to write interpreters that will use PyPy tools, that ends with ways of adding a JIT, so if you're interested be sure to come take a look :) (for people who don't have tickets yet: I'm sorry, we're sold out).