Metaclass system

• Moose is built on top of Class::MOP, also writen by Stevan Little
• A meta object protocol is an API to a language's object system
• Class::MOP is heavliy based on CLOS (Common Lisp Object System) and its meta object system.
• Art of the Metaobject Protocol (Gregor Kiczales, Jim Des Rivieres, Daniel G. Bobrow, Jim Des Rivieres)