This was made for a hackathon (hack the midwest). We intended to make a version of typeracer using code samples instead of prose.
Naturally things took longer than expected and we only really got as far being able to track/follow along with the code being typed. You can see it here: coderacer.
I (Curtis) wrote all the coffeescript (coderacer.coffee) for the code input, Caleb Hyde wrote the code to download and parse coding problem samples from Rosetta Code, the results of which can be found in data/parsed.
I later wrote some clojure to download more samples and store them in couchdb. I never got around to actual making use of the db once I had it though, maybe one day.