the common lisp object system
tutorials
warp speed intro >
http://home.comcast.net/~prunesquallor/guide.html
introduction (with an AI bent) >
http://www.apl.jhu.edu/~hall/AI-Programming/CLOS.html
http://alan.crowe.name/clos/define-method-combination.html
see also;
LISP
(via
Common Lisp
)