OOP to me means only messaging, local retention and protection and hiding of state-process, and extreme late-binding of all things. It can be done in Smalltalk and in LISP. There are possibly other systems in which this is possible, but I'm not aware of them. Dr. Alan Kay on the Meaning of "Object-Oriented Programming" 私が考えるOOPはメッセージング、状態処理のローカルでの保有・保護・隠蔽、そして全ての物に対する強力な遅延束縛、これだけだ。これはSmalltalkとLISP