The World Wide Web continues to grow and new technologies, modes of interactions, and applications are being developed. Building on this growth, Semantic Web technologies aim at providing a shared semantic information space, changing qualitatively our experiences on the Web. As Semantic Web technologies mature and permeate more and more application areas, new research challenges are coming to the fore and some unsolved ones are becoming more acute. These issues include creating and managing Semantic Web content, making Semantic Web applications robust and scalable, organizing and integrating information from different sources for novel uses, making semantics explicit in order to improve our overall experience with information technologies, and thus enabling us to use the wealth of information that is currently available in digital form for addressing our everyday tasks. To foster the exchange of ideas and collaboration, the International Semantic Web Conference brings together researchers in relevant disciplines such as artificial intelligence, databases, social networks, distributed computing, web engineering, information systems, natural language processing, and human-computer interaction. The Sixth International Semantic Web Conference (ISWC 2007), especially joined with the Second Asian Semantic Web Conference (ASWC2007), will truly play a vital role in promoting mutual cooperation, dissemination of research results and exchange of experiences.