This paper describes how we manage the interaction between different heterogeneous web services through choreographies within IRS-III.

IRS-III is a framework and platform for developing WSMO based semantic web services. Our choreography framework is based on the KADS system-client co-operation model that represents communication through two dimensions: the message direction and which actor has the initiative. Our formalism is state based and is thus compliant with Abstract State Machine (ASM) model used within WSMO.

In addition to describing our approach in this paper we provide a formal semantics for IRS Choreography and a full implementation which we illustrate through an example application.