[pjmlp]

Clojure supports protocols and multi-methods, the building blocks of CLOS, Common Lisp Object System.

Already at Xerox PARC, Lisps started to support OOP, with FLAVORS for Interlisp-D being one of the first ones.

EDIT: Disregard the last paragraph, lispm is right.

[lispm]

'Loops' was developed at Xerox PARC for Interlisp. Flavors was from MIT for Lisp Machine Lisp. Multimethods were first developed for Common Lisp in CommonLoops around 1986 at Xerox PARC.

[pjmlp]

Thanks for the correction. I typed it on the go without checking first.