How would you compare / contrast Chez and Racket? I'd be interested in hearing your thoughts.

From what I can tell (and I may be wrong), some differences are:

  - Chez has parallel threads (that can run on multiple cores)
  - Racket seems to have some higher level concepts and more learning material
  - Racket has multiple "languages" and facilitates making your own; see: Beautiful Racket[0]
  - Chez is faster than Racket

[0] https://beautifulracket.com/

Chez is a scheme, whereas Racket is basically a scheme but was renamed from PLT-Scheme because the authors/community felt it had strayed far enough from scheme that a renaming was a good idea.

It's still basically scheme though. I mean, if you're coming from a scheme background the only thing that might trip you up in racket is cons cells are immutable. If you only have racket experience and try out [another] scheme, you might experience some culture shock when you start encountering stuff like let-values being in srfi-11 instead of racket/base. In my opinion, racket is generally a more pleasant experience. Virtually all of my personal/recreational projects are in racket these days.

I like the fast 'bare bones' Chez implementation, but, I also appreciate the huge ecosystem around Racket.

Huge as in huge, or huge as in huge for a niche language?

Decide for yourself: https://pkgs.racket-lang.org/

Did I read ~1000 packages? That's great for a small community and bigger than last time I checked a few years ago. It has a long way to go to get to CPAN or Nuget size though (captain obvious to the rescue :)). I think it demonstrates that the community is healthy though and I like the packages I saw by some brief browsing.

The Racket standard library also has a lot of good stuff in it. There are many batteries included.