Applications that cross the boundaries of different computing machines, operating systems, and programming languages are increasingly the norm. As a result, the need for what might be called bridging technologies to develop software that works across heterogeneous environments has become more compelling. The Common Object Request Broker Architecture is one such technology that is both robust and commercially available. CORBA essentially describes how client applications can invoke operations on server objects using the services of an intermediary known as an Object Request Broker, or ORB. This article introduces CORBA by describing its key components. It then reviews the boundaries it helps to bridge. It concludes by comparing CORBA with a number of other bridging technologies available today.