Aw, why doesn't he mention Racket (formerly PLT Scheme)? I've been playing around with it since I saw it on HN a few weeks ago and it's a nifty implementation.

Aw, why doesn't he mention Racket (formerly PLT Scheme)? I've been playing around with it since I saw it on HN a few weeks ago and it's a nifty implementation. DrRacket is a great environment, and it seems like it has good library support - both lots of things available, and easy to drop in to your code, with (require ...).