(The hair in the ointment is the performance cost of message passing vs function calls.) Besides concurrency benefits of the actor model, message passing impli

(The hair in the ointment is the performance cost of message passing vs function calls.) Besides concurrency benefits of the actor model, message passing implicitly supports adaptive behavior. A message is, by definition, interpreted by the receiving actor. You can hot swap in Erlang precisely for this reason. "The key in making great and growable systems is much more to design how its modules communicate rather than what their internal properties and behaviors should be. Think of the internet - to live, it (a) has to allow many different kinds of ideas and realizations that are beyond any single standard and (b) to allow varying degrees of safe interoperability between these ideas. "If you focus on just messaging - and realize that a good metasystem can late bind the various 2nd level architectures used in objects - then much of the language-, UI-, and OS based discussions on this thread are really quite moot." http://wiki.c2.com/?AlanKayOnMessaging http://wiki.c2.com/?AlanKayOnMessaging So, it's this 'late binding' business -- the "interstitial" -- that is really interesting, powerful, and conceptually key to Kay's vision of organic systems. And this is basically reducible to one of the most powerful architectural concepts in software: indirection. https://en.wikipedia.org/wiki/Fundamental_theorem_of_software_engineering https://en.wikipedia.org/wiki/Fundamental_theorem_of_softwar... Now curious as to which of these two first grasped the beauty of indirection in structures.