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.
The new CMU CL compiler is called Python.
Version 17c includes an incremental compiler, profiler, run-time support, documentation, an editor and a debugger. It runs under Mach on SPARC, MIPS and IBM PC RT and under SunOS on SPARC.