Define a jacket and indicate how it might be used. Define an upcall and describe how it might be used. Describe how local RPC can be implemented using threads. Describe how remote RPC can be implemented using threads. O.S. emulation, language support.
Scheduling can occur in user-level modules.
May include communication to other processors, otherwise additional service. Interrupts, traps, exceptions. A process consists of an execution environment and one or more threads. No protection between threads. Thread shares address space.