[cgag]

We attempted to make something very similar at a hackathon. It's cool to see a more polished, complete version. Ours was more of an attempt to make a version of typeracer (http://play.typeracer.com/) using code samples from rosetta code. All we really got done though was handling typing the code (hilighting errors, letting you use tab for whitespace, etc), we didn't get around to recording stats.

This is all bringing back horrible memories of our disastrous demo actually, but very nice otherwise.