Medley was the last release of the Xerox Lisp environment, before the whole environment was renamed Medley. It was originally written in Interlisp (a dialect separate from the MACLISP/Common Lisp tradition, with its own ancestry), but later, Common Lisp also became part of the environment. Medley includes a WYSIWYG text editor (TEdit), email organizer (Lafite), performance tools (Spy) and many other libraries and user contributed code (from the 1980s).
It has been released under an MIT license together with an emulator which allows running it on modern hardware.
Paolo Amoroso has written a nice review.
Common Lisp in Medley is probably corresponding to CLtL1 https://github.com/Interlisp/medley/discussions/5, https://github.com/Interlisp/medley/discussions/280, so it should count as Common Lisp implementation.