Clojure is a dynamic programming language for the JVM. Note - current Clojure development has moved to Google code: http://code.google.com/p/clojure/ Project web site: http://clojure.org
SISC is an extensible Java based interpreter of the algorithmic language Scheme. SISC uses modern interpretation techniques, and handily outperforms all existing Java interpreters (often by more than an order of magnitude).