UNAS (Universal Network Architecture Services) A commercial product by TRW and Rational consisting of a suite of predefined, reusable Ada building blocks, services, and instrumentation that represent the high level primitives for the architecture of a distributed and heterogeneous software system. Provides core executive functions for distributed systems such as initialization, system mode control, reconfirmation, fault detection, health and status monitoring, and inter process communication. High Portability is supported.