AbstractDistributed programming can be greatly simplified by language support for distributed communication, such as that provided by remote procedure call (RPC) or remote object invocation. This paper examines design and implementation issues in these systems, and focuses on the influence of the communication system on a distributed program. To make the discussion concrete, we introduce a single application as implemented in two environments: Modula‐2+, an extension of Modula‐2 with RPC, and Emerald, an object‐based language that supports remote object invocation. We show that small differences in the implementation of the communication system can have a significant impact on how distributed applications are struc