I think the main difference is that Racket is a Scheme, and Common Lisp is, well, Common Lisp. Racket has some great tooling like their IDE (Dr Racket, already

I think the main difference is that Racket is a Scheme, and Common Lisp is, well, Common Lisp. Racket has some great tooling like their IDE (Dr Racket, already mentioned). Really it comes down to the old CL vs scheme thing, which seems to boil down to "has almost everything you need already but is huge" vs "lets you build anything you need yourself and is tiny." However, I think this is less so with Racket because, while I haven't used it much, from what I know it's more of a batteries-included scheme used for Getting Shit Done (and does a good job of this). If I was going to use a scheme and I didn't have the requirement of needing to embed it, I'd probably go with Racket.