In Object-Oriented Concurrent Programming, A. Yonezawa and M. Tokoro, eds., MIT Press, 1987. Concurrent Object-Oriented Programming in Act 1

To move forward to the next generation of artificial intelligence programs, new languages will have to be developed that meet the demanding requirements of these applications. Artificial intelligence software will require unprecedented flexibility, including the ability to support multiple representations of objects, and the ability to incrementally and transparently replace objects with new, upward-compatible versions. As advances in computer architecture and changing economics make feasible machines with large-scale parallelism, artificial intelligence will require new ways of thinking about computation that can exploit parallelism effectively. To realize this, we propose a model of computation based on the notion of actors, active objects that communicate by message passing. Actors blur the conventional distinction between data and procedures. For parallel computation, actors called futures create concurrency, by dynamically allocating processing resources. Serializers restrict concurrency by constraining the order in which events take place, and have changeable local state. The actor philosophy is illustrated by a description of our prototype actor interpreter Act 1. 1. Actors meet the requirements for organizing programs as societies What capabilities are needed in a computational model to construct models of intelligent processes as