This starts out at a pretty high-level ("What is a Lisp? What is Clojure?"), but eventually gets into some pretty interesting details about things like how Cloj

This starts out at a pretty high-level ("What is a Lisp? What is Clojure?"), but eventually gets into some pretty interesting details about things like how Clojure's immutable data structures are implemented (I'm only about halfway through so far)