Abstract: Requirements for interoperability and reusability motivate the use of object-oriented middleware like the Common Object Request Broker Architecture (CORBA). However, unless CORBA can be implemented efficiently, it will not be widely used in real-time and other latency-sensitive distributed applications. This paper presents three performance enhancement techniques for CORBA-based middleware. Two of these exploit limited heterogeneity in systems. In such a system a standard CORBA protocol is used when clients and servers interacting with one another are implemented by using different programming languages and/or operating systems. However, when a similar client-server pair built using the same technology communicates, a number of CORBA operations are bypassed thus reducing the communication overhead. Based on a commercial middleware product and measurements made on a performance prototype running on a network of workstations, this research demonstrates that there is a strong potential for achieving a significant performance improvement by incorporating these techniques into the middleware.