Connected to theseus. System is scalable and allows dynamic configuration over a wide range of platforms. The creator can spread this knowledge as desired. Additionally, the address space is split into a user and system space.
Threads can access the system space depending on whether they are trusted and privileged.
Users are neither, the system is trusted, and the supervisor is both. Ports can be migrated between actors, and can be dynamically added into port groups for multi-cast and duplication services. Pages are paged on demand. Everything can be run without modification or recompilation, except for the interrupt handlers. The introduction of multi-threading in UNIX processes makes signaling more difficult.