Carl Hewitt [1985] argued that because of the use of Arbiters that the Actor model was more powerful than logic programming (see indeterminacy in concurrent computation).
A family of Prolog-like concurrent message passing systems using unification of shared variables and data structure streams for messages were developed by Keith Clark, Hervé Gallaire, Steve Gregory, Vijay Saraswat, Udi Shapiro, Kazunori Ueda, etc.
Issues of compositionality had proven to be serious limitations for previous theories of computation including the lambda calculus and Petri nets.
Researchers at Caltech under the leadership of Chuck Seitz developed the Cosmic Cube which was one of the first message-passing Actor architectures.
Kohei Honda and Mario Tokoro 1991, José Meseguer 1992, Ugo Montanari and Carolyn Talcott 1998, M. Gaspari and G. Zavattaro 1999 have attempted to relate Actor semantics to algebra.
Local concurrency is being enabled by new hardware for 64-bit many-core microprocessors, multi-chip modules, and high performance interconnect.