Cedar
A superset of Mesa, from Xerox PARC, adding garbage collection, dynamic types and a universal pointer type (REF ANY). Cedar is a large complex language designed for custom Xerox hardware and the Cedar operating system/environment. Data types are atoms, lists, ropes ("industrial strength" strings), conditions. Multi-processing features include threads, monitors, signals and catch phrases. It was used to develop the Cedar integrated programming environment.
["A Description of the Cedar Language", Butler Lampson, Xerox PARC, CSL-83-15 (Dec 1983)].
["The Structure of Cedar", D. Swinehart et al, SIGPLAN Notices 20(7):230-244 (July 1985)].