Ready Lisp is complete Common Lisp environment for your Mac, packaging together all the current open source greats, like Aquamacs Emacs, SBCL Common Lisp, and the SLIME Lisp IDE. It's a single application bundle, so all you have to do is download and double-click, and you'll be running ANSI Common Lisp!
TUISHIMI No review... just commenting that I think it is great that people still port/support development environments like LISP (which in great part gave rise to the awesome languages such as ruby, io, python and others).