Hemlock

Hemlock is a free Emacs text editor for most POSIX-compliant Unix systems. It follows the tradition of the Lisp Machine editor ZWEI and the ITS/TOPS-20 implementation of Emacs, but differs from XEmacs or GNU Emacs, the most popular Emacs variants, in that it is written in Common Lisp rather than Emacs Lisp and C—although it borrows features from the later editors. Hemlock was originally written by the CMU Spice project in Spice Lisp (later renamed to CMU Common Lisp) for the PERQ computer.