Heiner Stuckenschmidt holds a post-doc position in the Knowledge Representation and Reasoning Group at the Vrije Universiteit Amsterdam where he received his PhD for work on Ontology-Based Information Sharing on the Semantic Web. His works include Semantic Web related topics such as ontology languages, knowledge-based meta data management and robust and scalable terminological reasoning. Before moving to Amsterdam, he was employed as a researcher and lecturer at the University of Bremen. His research activities in Bremen included the application of ontologies for information sharing in web based information systems with a special focus on semantics-preserving information integration and spatially related information.

He is organizer of a series of workshops on ontologies at international conferences (IJCAI01, ECAI02, IJCAI03) and member of program committees of several semantic web related conferences (SWWS01, ISWC02, WWW03) and has held / will hold tutorial on the topic of the proposed book at different conferences (K-CAP 2001, IJCAI03, ISWC03). He is editor of a book on the application of ontologies in the cadastral domain and has published more than 40 paper in international journals, conferences and workshops.

Frank van Harmelen is professor in Knowledge Representation and Reasoning at the Department of Artificial Intelligence of the Vrije Universiteit Amsterdam. He was awarded a PhD from the Department of AI in Edinburgh for his research on meta-level reasoning, after having studied Mathematics and Computer Science in Amsterdam. He is author of a book on meta-level inference, editor of a book on knowledge-based systems, editor of a book on KnowledgeManagement on the Semantic Web, and is currently preparing a text-book on Semantic Web languages. He has published over 100 papers, many of them in leading journals and conferences. He has made key contributions to the CommonKADS project by providing a formal basis for the conceptual models. More recently, he has been co-projectmanager of the On-To-Knowledge project, and was one of the designers of OIL, which (in its form DAML +OIL) is currently the basis for a W3C standardized Web ontology language.

He is a member of the joint EU/US committee on agent markup languages (who designed DAML+OIL), and is an active member of the W3C working group on Web Ontology languages, responsible for the OWL Web Ontology Language. He was the 2002 Program Chair of the European Conference on Artificial Intelligence, and will be the General Chair of the 2004 International Semantic Web Conference.