The ActorSpace model is based on message passing, but allows the user to specify a more abstract destination of messages. This decouples individual actors from each other and makes ActorSpace well suited for expressing open distributed systems, which may run on different architectures. ActorSpace supports heterogeneous computing by using the message passing facilities as an encapsulation of the individual actor's state. ActorSpace supports an open system by using a pattern as a specification of the receiving group of actors. By using the ActorSpace communication primitives, executing actors will not be aware that other actors may be executing on different architectures. The result of this is that actors can join and later leave an ongoing computation or make use of an available service without a specific connection to a set of computing actors or a server.