[racket] Is Racket have Lisp's dynamic code change ability?

> As a beginner I'm researching the capabilities of Scheme versus CL. As I
> understand, CL allows for changing the code as it is running in the REPL (as
> advertised in StumpWM, "Lisp at JPL" etc.). Does Racket allow this?

Have you seen the section in the documentation that talks about
dynamic evaluation?

    http://docs.racket-lang.org/guide/reflection.html