This comprehensive text explains the principles and practice of Web services and relates all concepts to practical examples and emerging standards. Its discussions include: * Ontologies * Semantic web technologies * Peer-to-peer service discovery * Service selection * Web structure and link analysis * Distributed transactions * Process modelling * Consistency management. The application of these technologies is clearly explained within the context of planning, negotiation, contracts, compliance, privacy, and network policies. The presentation of the intellectual underpinnings of Web services draws from several key disciplines such as databases, distributed computing, artificial intelligence, and multi-agent systems for techniques and formalisms. Ideas from these disciplines are united