Service-Oriented Computing is one of the most promising software engineering trends for future distributed systems. Currently there are many different approaches to semantic web service descriptions and many frameworks built around them. Yet a common understanding, evaluation scheme, and test bed to compare and classify these frameworks in terms of their abilities and shortcomings, is still missing. This book is an edited volume that develops this common understanding of the various technologies intended to facilitate the automation of mediation, choreography and discovery for Web Services using semantic annotations. The book is designed for a professional audience composed of practitioners and researchers in industry. Professionals can use this book to evaluate SWS technology for their potential practical use. The book is also suitable for advanced-level students in computer science.