Rich Hickey mentions 'egal' in a few of his videos. One is particular is the Clojure for Lisp Programmers. The particular spot is around 1:07 minutes in at slide 32 on Equality.
Link to Paper
Link to Henry Baker's egal Paper
Link to Video
http://clojure.blip.tv/file/1313503/">Clojure for Lisp Programmers Part 2