The use of Semantic Web Services (SWS) for increasing agility and adaptability in process execution is currently investigated in many settings. The common underlying idea is the dynamic selection, composition and mediation on the basis of available SWS descriptions – of the most adequate Web resource (services and data) to accomplish a specific process activity. In this paper we describe IRS-III, a framework for creating and executing semantic Web services, which takes a semantic broker based approach to mediating between service requesters and service providers. We describe the overall approach of IRS-III from an ontological perspective. We then illustrate our approach through three different applications to domains of Business Process Management, e-Learning and e-Science.