CMU Common Lisp
(CMU CL) A public domain "industrial strength" Common Lisp programming environment. Many of the X3J13 changes have been incorporated into CMU CL. Wherever possible, this has been done so as to transparently allow use of either CLtL1 or proposed ANSI CL. Probably the new features most interesting to users are SETF functions, LOOP and the WITH-COMPILATION-UNIT macro.