My latest creation using Lisa on ABL (armed-bear Lisp):

http://jlisa.sourceforge.net

.... imagine evaluating rules like this one:

(defrule climb-to-hold ()
  (goal-is-to (action hold) (argument-1 ?obj))
  (thing (name ?obj) (location ?place (not ceiling))
         (on-top-of ?on) (weight light))
  (monkey (location ?place) (on-top-of (not ?on)))
  (not (goal-is-to (action on) (argument-1 ?on)))
  =>
  (assert ((make-instance 'goal-is-to :action 'on :argument-1 ?on))))

on Java objects, while having all the power of CommonLisp available.

MikeBeedle