Smalltalk and Self use prototyping for inheritance, like JavaScript and Lua. It's a dynamically typed version of subclassing, where your parent is itself a live object, not just a definition. I suppose it's proxy-like, except forwarding of messages/method invocations is automatic and part of the language semantics, and the context object (self) is the one used in the caller's invocation.

I've not used Objective C much, but I believe the core of Objective C works the same--non-overridden methods (message handlers) of an instantiated object are invoked using the parent prototype's instance definition. Objective C derives both it's semantics and technical jargon (e.g. selectors) straight from Smalltalk. But it also supports so-called protocols, aka interfaces in other languages, which because it's a more familiar paradigm seems to be how most people associate OOP with Objective C.

I guess I'm making a hash of it, but in any event the end result is quite similar to if not largely indistinguishable from class inheritance. And because it's all dynamic, and depending on the language mechanics and your particular masochistic proclivities, it's even often quite straight forward to achieve multiple inheritance, e.g. in Smalltalk or Lua using a catch-all/fallback handler to select a method from a second (or third, fourth, etc) prototype subtree.