Actors <theory> A model for {concurrency} by {Carl Hewitt}. Actors are autonomous and concurrent {objects} which execute {asynchronously}. The Actor model provides flexible mechanisms for building parallel and {distributed} software systems. (http://osl.cs.uiuc.edu/). ["Laws for Communicating Parallel Processes", C. Hewitt et al, IFIP 77, pp. 987-992, N-H 1977]. ["ACTORS: A Model of Concurrent Computation in Distributed Systems", Gul A. Agha <[email protected]>, Cambridge Press, MA, 1986]. (1999-11-23)