From: transfire@... Date: 2006-06-19T12:13:18+09:00 Subject: Re: About , meta class and Cl Maybe this helps: /* * Ruby's Class Hierarchy Chart * * +------------------+ * | | * Object---->(Object) | * ^ ^ ^ ^ | * | | | | | * | | +-----+ +---------+ | * | | | | | * | +-----------+ | | * | | | | | * +------+ | Module--->(Module) | * | | ^ ^ | * OtherClass-->(OtherClass) | | | * | | | * Class---->(Class) | * ^ | * | | * +----------------+ * * + All metaclasses are instances of the class `Class'. */ T. P.S. Recently noticed Smalltalk uses the term metaclass. I wonder why singleton took it's place?