Breuker (Leibniz Center for Law, U. of Amsterdam, the Netherlands), Casanovas (Institute of Law and Technology, Autonomous U. of Barcelona, Spain), Klein (mathematics and computer science, Vrije U. Amsterdam, the Netherlands), and Francesconi (Insituto di Teoria e Techniche dell'Informazione Giuridica, Centro Nationale de la Ricerca, Italy) present 11 papers intended to provide a representative overview of the state of the art in legal ontologies (forms of knowledge representation) and semantic web technology, covering both theoretical aspects and practical systems The theoretical chapters discuss such topics as pattern-based design for legal ontologies, ontology learning from Italian legal texts, automatic extraction and ontology acquisition of definitions in court decisions, and automatic argumentation detection and its role in law and the semantic web. The applications section contains papers discussing matching law ontologies using an extended argumentation framework based on confidence degrees, an ontology-based decision support system for judges, a two-level knowledge approach to support multilingual legislative drafting, and a procedural ontology for legal multimedia applications in the Spanish civil courts. Annotation ©2009 Book News, Inc., Portland, OR (booknews.com)