This book constitutes the refereed proceedings of the Second International Semantic Web Conference, ISWC 2003, held at Sanibel Island, Florida, USA in October 2003. The 58 revised full papers presented were carefully reviewed and selected from numerous submissions. The papers are organized in topical sections on foundations; ontological reasoning; semantic Web services; security, trust, and privacy; agents and the semantic Web; information retrieval; multimedia; tools and methodologies; applications; and industrial perspectives.

These proceedings contain the papers accepted for presentation at the Second International Semantic Web Conference (ISWC 2003) held on Sanibel Island, Florida, U. S. A. , October 20–23, 2003. Following the success of ISWC 2002 that washeldinSardiniainJune2002,ISWC2003enjoyedagreatlyincreasedinterest in the conference themes. The number of submitted papers more than doubled compared with ISWC 2002 to 283. Of those, 262 were submitted to the research track and 21 to the industrial track. With rare exceptions, each submission was evaluated by three program committee members whose reviews were coordinated by members of the senior program committee. This year 49 papers in the research track and 9 papers in the industrial track were accepted. The high quality of ISWC 2003 was the result of the joint e?ort of many people. First of all we would like to thank the authors for their high-quality submissions and the members of the program committee for their reviewing and review coordination e?orts. We would like to extend special thanks to Christoph Bussler for chairing the industrial track, to Mike Dean for his help with the conference management software, the web site, and conference publicity, and to Massimo Paolucci for helping with the organization of the proceedings and arranging sponsorships.

These proceedings contain the papers accepted for presentation at the Second International Semantic Web Conference (ISWC 2003) held on Sanibel Island, Florida, U. S. A. , October 20–23, 2003. Following the success of ISWC 2002 that washeldinSardiniainJune2002,ISWC2003enjoyedagreatlyincreasedinterest in the conference themes. The number of submitted papers more than doubled compared with ISWC 2002 to 283. Of those, 262 were submitted to the research track and 21 to the industrial track. With rare exceptions, each submission was evaluated by three program committee members whose reviews were coordinated by members of the senior program committee. This year 49 papers in the research track and 9 papers in the industrial track were accepted. The high quality of ISWC 2003 was the result of the joint e?ort of many people. First of all we would like to thank the authors for their high-quality submissions and the members of the program committee for their reviewing and review coordination e?orts. We would like to extend special thanks to Christoph Bussler for chairing the industrial track, to Mike Dean for his help with the conference management software, the web site, and conference publicity, and to Massimo Paolucci for helping with the organization of the proceedings and arranging sponsorships.

The 3rd International Semantic Web Conference (ISWC 2004) was held Nov- ber 7–11, 2004 in Hiroshima, Japan. If it is true what the proverb says: “Once by accident, twice by habit, three times by tradition,” then this third ISWC did indeed ?rmly establish a tradition. After the overwhelming interest in last year’s conference at Sanibel Island, Florida, this year’s conference showed that the Semantic Web is not just a one-day wonder, but has established itself ?rmly on the research agenda. At a time when special interest meetings with a Sem- tic Web theme are springing up at major conferences in numerous areas (ACL, VLDB, ECAI, AAAI, ECML, WWW, to name but a few), the ISWC series has established itself as the primary venue for Semantic Web research. Response to the call for papers for the conference continued to be strong. We solicited submissions to three tracks of the conference: the research track, the industrial track, and the poster track. The research track, the premier venue for basic research on the Semantic Web, received 205 submissions, of which 48 were accepted for publication. Each submission was evaluated by three p- gram committee members whose reviews were coordinated by members of the senior program committee. Final decisions were made by the program co-chairs in consultation with the conference chair and the senior program committee. The industrial track, soliciting papers describing industrial research on the - mantic Web, received 22 submissions, of which 7 were accepted for publication.

This book constitutes the refereed proceedings of the 4th International Semantic Web Conference, ISWC 2005, held in Galway, Ireland, in November 2005. The 54 revised full academic papers and 17 revised industrial papers presented together with abstracts of 3 invited talks were carefully reviewed and selected from a total of 217 submitted papers to the academic track and 30 to the industrial track. The research papers address all current issues in the field of the semantic Web, ranging from theoretical aspects to various applications. The industrial track contains papers on applications in particular industrical sectors, new technology for building applications, and methodological and feasibility aspects of building industrical applications that incorporate semantic Web technology. Short descriptions of the top five winning applications submitted to the Semantic Web Challenge competition conclude the volume.

This book constitutes the refereed proceedings of the 5th International Semantic Web Conference, ISWC 2006, held in Athens, GA, USA in November 2006. It features more than 52 papers that address all current issues in the field of the semantic Web, ranging from theoretical aspects to various applied topics. An additional 14 papers detail applications in government, public health, public service, academic, and industry.

As the Web continues to grow, increasing amounts of data are being made available for human and machine consumption. This emerging Semantic Web is rapidly entering the mainstream and, as a result, a variety of new solutions for searching, aggregating and the intelligent delivery of information are being produced,bothinresearchandcommercialsettings.Severalnewchallengesarise from this context, both from a technical and human–computer interaction p- spective – e.g., as issues to do with the scalability andusability of Semantic Web solutions become particularly important. The International Semantic Web Conference (ISWC) is the major inter- tional forum where the latest research results and technical innovations on all aspects of the Semantic Web are presented. ISWC brings together researchers, practitioners, and users from the areas of arti?cial intelligence, databases, social networks,distributedcomputing,Webengineering,informationsystems,natural language processing, soft computing, and human–computer interaction to d- cuss the major challenges and proposed solutions, success stories and failures, as well the visions that can advance the ?eld.