NETWORK OBJECTS

A network object is an object whose methods can be invoked over a netw ork, The Modula-3 network objects system is novel for its overall simp licity, It provides distributed type safety through the narrowest surr ogate rule, which allows programmers to export new versions of distrib uted services as subtypes of previous versions, The design and impleme ntation of the system is described, including a thorough description o f realistic marshaling algorithms for network objects, precise informa l specifications of the major system interfaces, lessons learned from using the system, and performance results.