The publication by Tony Hoare in 1978 of the original Communicating Sequential Processes was different from the Actor model which states:[3] The 1978 version of CSP differed from the Actor model in the following respects [Clinger 1981]: In his Turing lecture,[4] Milner remarked as follows: In 2003, Ken Kahn recalled in a message about the Pi calculus: Tony Hoare, Stephen Brookes, and A. W. Roscoe developed and refined the theory of CSP into its modern form.
[5] The approach taken in developing the theoretical version of CSP was heavily influenced by Robin Milner's work on the Calculus of Communicating Systems (CCS), and vice versa.
Bill Kornfeld and Carl Hewitt [1981] showed that the Actor model could encompass large-scale concurrency.
Sangiorgi and Walker [citation needed] showed how Actor work on treating control structures as patterns of passing messages[8] could be modeled using the π-calculus.
Although algebraic laws have been developed for the Actor model, they do not capture the crucial property of guaranteed delivery of messages sent to Serializers.