An object-oriented Lisp developed by Lisp Machines Inc. (LMI) in about 1987. Object Lisp was based on nested closures and operator shadowing.
Several competing object-oriented extensions to Lisp were around at the time, such as Flavors, in use by Symbolics; Common Objects, developed by Hewlett-Packard; and CommonLoops in use by Xerox.
LMI submitted the specification as a candidate for an object-oriented standard for Common Lisp, but it was defeated in favour of CLOS.
["ObjectLISP User Manual", G. Dreschere, LMI 1987].