New and innovative hardware mechanisms for efficient message passing and object invocation in a distributed computing system are being designed and developed. Operating systems structures for a distributed environment follow one of two paradigms: message passing or object invocation. For such a system to perform efficiently basic messages must be passed with short delays. The limiting factor, especially for short messages, is typically not network bandwidth but processing overhead. Resources in an operating system can also be viewed as a collection of objects. Previous research of the principal investigator has shown that object invocation is dependent on the efficiency of memory management. The principal investigator is currently extending his previous performance studies on message-based systems, verifying these studies through experimentation, investigating hardware support for networked shared-memory multiprocessors; developing new hardware mechanisms for efficient object invocation, and evaluating these mechanisms through simulation and experimentation.