Theoretical Aspects of Communication-Centred Programming 1

This short note outlines two different ways of describing communication-centric software in the form of formal calculi and discuss their relationship. Two different paradigms of description, one centring on global message flows and another centring on local (end-point) behaviours, share the common feature, structured representation of communications. The global calculus originates from Web Services - Choreography Description Language (WS-CDL), a web service description language developed by W3C's WS-CDL Working Group. The local calculus is based on the π-calculus, one of the representative calculi for communicating processes. We illustrate these two descriptive frameworks, outline the static and dynamic semantics of these calculi, and discuss the basic idea of end-point projection, by which any well-formed description in the global calculus has a precise representation in the local calculus.