Though this is not at all the only essential part of Racket, building other languages atop it is something Racket really specializes at, which Clojure does not.

Though this is not at all the only essential part of Racket, building other languages atop it is something Racket really specializes at, which Clojure does not. See http://cs.brown.edu/~sk/Publications/Papers/Published/fffkbmt-programmable-prog-lang/ http://cs.brown.edu/~sk/Publications/Papers/Published/fffkbm.... Of course, Clojure rocks running atop the JVM, with all the attendant engineering benefit that provides down below; Racket doesn't do that (and can't; its VM has to be specialized to support various control features, etc., that the JVM doesn't provide).