[racket] Racket on Racket?

There is -- that's the Honu language.  This is a very ambitious syntax
design built entirely on top of Racket, with infix and what not, with
the added benefit that you ought to be able to embed Honu expressions
(h-expressions) inside Racket programs.

(I should not say much to avoid misleading readers, because to me Honu
has always been two things: a *syntax* experiment and a *semantics*
experiment.  I don't know how much either or both of those is still
true.)

Shriram