MIT ran(/runs?) a one-month short course covering material from 6.001, and they used PLT Scheme when I took it (now Racket). I seem to remember needing to go into one of the rnrs language modes to get things like mutable cons cells. (How impure.) From what I understand, MIT Scheme is much more in the Maclisp tradition, vs. Racket being more from programming language theory (though both are firmly rooted in the Scheme standard), which reflects in their extensions to the core language.
Nowadays, there is no equivalent to 6.001 at MIT, except maybe 6.945 can substitute. They have a survey course sequence 6.01/6.02 which covers EECS in general, using Python when programming is needed. As a challenge exercise you can make an interpreter for a language, though that's not very metacircular.