The way in which application systems and software are built has changed dramatically over the past few
years. This is mainly due to advances in hardware technology, programming languages, as well as the
requirement to build better software application systems in less time. The importance of mondial (worldwide)
communication between systems is also growing exponentially. People are using network-based
applications daily, communicating not only locally, but also globally. The Internet, the global network,
therefore plays a significant role in the development of new software. Distributed object computing is one
of the computing paradigms that promise to solve the need to develop clienVserver application systems,
communicating over heterogeneous environments.
This study, of limited scope, concentrates on one crucial element without which distributed object computing
cannot be implemented. This element is the communication software, also called middleware, which allows
objects situated on different hardware platforms to communicate over a network. Two of the most important
middleware standards for distributed object computing today are the Common Object Request Broker
Architecture (CORBA) from the Object Management Group, and the Distributed Component Object
Model (DCOM) from Microsoft Corporation. Each of these standards is implemented in commercially
available products, allowing distributed objects to communicate over heterogeneous networks.
In studying each of the middleware standards, a formal way of comparing CORBA and DCOM is presented,
namely meta-modelling. For each of these two distributed object infrastructures (middleware), meta-models
are constructed. Based on this uniform and unbiased approach, a comparison of the two distributed object
infrastructures is then performed. The results are given as a set of tables in which the differences and
similarities of each distributed object infrastructure are exhibited. By adopting this approach, errors caused
by misunderstanding or misinterpretation are minimised. Consequently, an accurate and unbiased
comparison between CORBA and DCOM is made possible, which constitutes the main aim of this
dissertation.ComputingM. Sc. (Computer Science
