Engineering CORBA-based distributed systems

Development of distributed applications is a difficult task. Object Requests Brokers (ORBs) facilitate the development of large and complex distributed applications. However, the programmer still has to deal with a complex framework, which increases the learning curve. In this paper, we present a middleware that tries to facilitate the transition from the design to the implementation. The middleware is made up of a C++ framework and an Agent Definition Language (ADL). The framework is implemented on top of a CORBA ORB and provides the programmer with high-level abstractions, such as "agent" and "FUN" (a special class of agent that delegate part of its functionality into a number of cooperating agents). ADL is a template-like language, which hides the underlying C++ framework from the programmer (including the CORBA ORB). The paper makes special emphasis in describing such a language.