This book presents thoroughly revised tutorial papers based on lectures given by leading researchers at the First Summer School on Reasoning Web in Msida, Malta, in July 2005. The objective is to provide a coherent introduction into Semantic Web methods and issues with a particular focus on reasonning.The ten tutorial papers presented provide competent coverage of methods and issues of the Semantic Web, ontology languages and their relation to description logics, Web query languages, XML, RDF and topics maps, evolution and reactivity, personalization in the Semantic Web, rule modeling with UML, techniques in Web information extraction, employing ontologies to ease construction of software applications, and type checking for Web rule and query languages.