Except note that Pyret is not implemented atop Racket. It used to be (a #lang) but that proved not suitable for our needs, so we built a very sophisticated run-

Except note that Pyret is not implemented atop Racket. It used to be (a #lang) but that proved not suitable for our needs, so we built a very sophisticated run-time system on top of JavaScript. Pyret now compiles to JavaScript entirely in the browser (and Pyret's compiler is written in Pyret itself, so it's all bootstrapped goodness). That said, Racket is indeed a fantastic next language after Pyret. I myself constantly switch between the two.