Languages / Concept
The Actor Model
Everything is an actor; the only verb is "send".
Carl Hewitt, with Peter Bishop and Richard Steiger, proposed the actor model in 1973 as a theory of concurrent computation. An actor is a self- contained thing that can do only three things in response to a message: send messages to other actors, create new actors, and decide how it will handle the next message. There is no shared state — only messages.
Erlang is the model’s most successful practical embodiment, arrived at largely independently from telecom needs rather than theory. The same ideas power Akka on the JVM and shape how modern systems think about distribution and failure.
Sources
- Hewitt, Bishop & Steiger, “A Universal Modular ACTOR Formalism for Artificial Intelligence” (1973) — the paper that proposed actors.
See also: Erlang.