I have been reading Christian Queinnec's Lisp in Small Pieces over the past couple of weeks. It's a fascinating book that goes through the implementation of a few Lisp implementations (Scheme mostly, but various CL features are also covered in good detail). It covers both interpreters and compilers and brings out a lot of issues with the implementation of various features. For instance, it has a whole chapter devoted to the Lisp-1 vs. Lisp-2 debate and shows how each of the various systems is implemented behind the scenes. It covers continuations extensively. The book is pretty expensive (~$75 USD) but it's also very deep. WARNING: heavy reading! Non-trivial coverage of things like lambda calculus and denotional semantics. If you want a book to teach you how to program in Scheme or Lisp, this is not it.