Championed by the 3W Consortium, the Semantic Web is a highly significant initiative affecting the future of the World Wide Web. Currently, web-based information comprises primarily documents written in HTML (HyperText Markup Language). Today´s web, however, offers only very limited ways of describing the content itself. The Semantic Web addresses this shortcoming, using the descriptive technologies RDF (Resource Description Framework) and OWL (Web Ontology Language), and the data-centric, customizable XML (Extensible Markup Language). They envision knowledge workplaces where the boundaries between document management, content management, and knowledge management are broken down, and where knowledge management is an effortless part of day-to-day activities. It provides a comprehensive overview of the state-of-the art in Semantic Web research and key technologies. It examines how Semantic web technology is being applied in knowledge management (Semantic Information Access) and in the next generation of web services. It addresses the issues of (semi-) automatic ontology generation and metadata extraction. It discusses ontology management and evolution, covering language - independent ontology evolution, ontology change request specification, and ontology dependency. It includes contributions by the top authorities in the field and illustrates the theoretical concepts with three case studies on industrial applications in digital libraries, the legal sector and the telecommunication industry. It is suitable for undergraduates and graduate students, academics, industrial researchers in the field and industrial personnel who are tracking WWW technology developments in order to understand the business implications.