The vision of the Semantic Web is to enhance today’s Web by exploiting machine-processable metadata. The explicit representation of the semantics of data, enriched with domain theories (ontologies), will enable a web that provides a qualitatively new level of service. It will weave together a large network of human knowledge and makes this knowledge machine-processable. Various automated services will help the users to achieve their goals by accessing and processing information in machine-understandable form. This network of knowledge systems will ultimately lead to truly intelligent systems, which will be employed for various complex decision-making tasks. Semantic Web research can benefit from ideas and cross-fertilization with many other areas: Artificial Intelligence, Natural Language Processing, Databases and Information Systems, Information Retrieval, Multimedia, Distributed Systems, Social Networks and Web Engineering. Many advances within these areas can contribute towards the realization of the Semantic Web.

The 6th Annual European Semantic Web Conference (ESWC 2009) will present the latest results in research and applications of Semantic Web technologies. ESWC 2009 will also feature a tutorial program, system descriptions and demos, a posters track, a Ph.D. symposium and a number of collocated workshops.