Connectors in configuration programming languages: are they necessary?

Configuration programming is the process whereby components written in any conventional programming language can be bound together to form a dynamic system, often suitable for execution on distributed hardware. Among the specialised languages that exist for configuration programming there is currently a debate over the importance of recognising the connections between components as being as important as the components themselves. The paper lays out the pros and cons of the debate, outlining in the process the properties and roles of connectors. By means of experiments we show how connectors influence the way configurations are programmed and also how some of the effects can be simulated. The examples are given in Darwin, UNICON and WRIGHT and reference is also made to the status of other current configuration languages.