This book constitutes the refereed proceedings of the 9th Extended Semantic Web Conference, ESWC 2012, held in Heraklion, Crete, Greece, in May 2012. The 53 revised full papers presented were carefully reviewed and selected from 212 submissions. They are organized in tracks on linked open data, machine learning, natural language processing and information retrieval, ontologies, reasoning, semantic data management, services, processes, and cloud computing, social Web and Web science, in-use and industrial, digital libraries and cultural heritage, and e-government. The book also includes 13 PhD papers presented at the PhD Symposium.

The Semantic Web aims at enriching the existing Web with meta-data and processing methods so as to provide web-based systems with advanced capabilities, in particular with context awareness and decision support. The objective of this book is to provide a coherent introduction to semantic web methods and research issues with a particular emphasis on reasoning.

The 7th reasoning web Summer School, held in August 2011, focused on the central topic of applications of reasoning for the emerging Web of Data . The 12 chapters in the present book provide excellent educational material as well as a number of references for further reading. The book not only addresses students working in the area, but also those seeking an entry point to various topics related to reasoning over Web data. "

Service-oriented computing is an emerging factor in IT research and development. Organizations like W3C and the EU have begun research projects to develop industrial-strength applications. This book offers a thorough, practical introduction to one of the most promising approaches - the Web Service Modeling Ontology (WSMO). After a brief review of technologies and standards of the Worldwide Web, the Semantic Web, and Web Services, the book examines WSMO from the fundamentals to applications in e-commerce, e-government and e-banking; it also describes its relation to OWL-S and WSDL-S and other applications. The book offers an up-to-date introduction, plus pointers to future applications.

ThepromiseoftheSemanticWeb, atits most expansive, is to allow knowledge to be freely accessed and exchanged by software. It is now recognized that if the SemanticWebis to containdeepknowledge, theneedfornewrepresentationand reasoning techniques is going to be critical. These techniques need to ?nd the righttrade-o?betweenexpressiveness, scalabilityandrobustnesstodealwiththe inherently incomplete, contradictory and uncertain nature of knowledge on the Web. The International Conference on Web Reasoning and Rule Systems (RR) was founded to address these needs and has grown into a major international forum in this area. The third RR conference was held during October 25-26, 2009 in Chantilly, Virginia, co-located with the International Semantic Web Conference (ISWC 2009). This year 41 papers were submitted from authors in 21 countries. The P- gram Committee performed outstandingly to ensure that each paper submitted to RR 2009 was thoroughly reviewed by at least three referees in a short - riod of time. The resulting conference presented papers of high quality on many of the key issues for reasoning on the Semantic Web. RR 2009 was fortunate to have two distinguished invited speakers. Robert Kowalski, in his talk "- tegrating Logic Programming and Production Systems with Abductive Logic Programming Agents" addressed some of the fundamental considerations - hind reasoning about evolving systems. Benjamin Grossof's talk "SILK: Higher Level Rules with Defaults and Semantic Scalability" described the design of a major next-generation rule system. The invited tutorial "Uncertainty Reas- ing for the Semantic Web" by Thomas Lukasiewicz provided perspectives on a central issue in this area.

These are the proceedings of the 12th international workshop on cooperative informationagents(CIA2008), heldattheCzechTechnicalUniversityinPrague, Czech Republic, on September 10-12, 2008. In today's world of ubiquitously connected heterogeneous information s- tems, business services and computing devices, the intelligent coordination and provisionofrelevantadded-value informationor servicesto the user atany time, anywhere is of key importance to a variety of applications. This challenge is - visioned to be coped with by means of appropriate intelligent and cooperative information agents. An intelligent information agent is a computational software entity that is capable of accessing one or multiple, potentially heterogeneous and distributed information sources, proactively acquiring, mediating, and maintaining relevant information or services on behalf of its human users, or other agents, preferably just in time and anywhere. One key challenge of developing intelligent and - operative information systems is to balance the autonomy of networked data, information, and knowledge sourceswith the potential payo?of leveragingthem by the appropriate use of such agents. Researchonintelligentinformationagentsandsystemsisinherentlycrossd- ciplinary covering themes from domains such as AI, Multiagent Systems, HCI, SemanticWebTechnologies, WebServices, InformationSystems, KnowledgeD- covery, Information Retrieval, and P2P Computing.

Service-oriented computing has become one of the predominant factors in current IT research and development. Web services seem to be the middleware solution of the future for highly interoperable distributed software solutions. In parallel, research on the Semantic Web provides the results required to exploit distributed machine-processable data. To combine these two research lines into industrial-strength applications, a number of research projects have been set up by organizations like W3C and the EU.

Dieter Fensel and his coauthors deliver a profound introduction into one of the most promising approaches the Web Service Modeling Ontology (WSMO). After a brief presentation of the underlying basic technologies and standards of the World Wide Web, the Semantic Web, and Web Services, they detail all the elements of WSMO from basic concepts to possible applications in e-commerce, e-government and e-banking, and they also describe its relation to other approaches like OWL-S or WSDL-S.

While many of the related technologies and standards are still under development, this book already offers both a broad conceptual introduction and lots of pointers to future application scenarios for researchers in academia and industry as well as for developers of distributed Web applications.

This book constitutes the proceedings of the satellite events held at the 17th Extended Semantic Web Conference, ESWC 2020, in May/June 2020. The conference was planned to take place in Heraklion, Crete, Greece, but changed to an online format due to the COVID-19 pandemic. ESWC is a major venue for presenting and discussing the latest scientific results and technology innovations related to the Semantic Web, Linked Data and Knowledge Graphs. The 36 poster and demo papers, 7 PhD symposium papers, and 4 industry track papers, included in this volume were carefully reviewed and selected from 59 submissions to the poster and demo track; 11 submissions to the PhD symposium track, and 5 submissions to the Industry track.

The two volume set LNCS 12506 and 12507 constitutes the proceedings of the 19th International Semantic Web Conference, ISWC 2020, which was planned to take place in Athens, Greece, during November 2-6, 2020. The conference changed to a virtual format due to the COVID-19 pandemic. The papers included in this volume deal with the latest advances in fundamental research, innovative technology, and applications of the Semantic Web, linked data, knowledge graphs, and knowledge processing on the Web. They were carefully reviewed and selected for inclusion in the proceedings as follows: Part I: Features 38 papers from the research track which were accepted from 170 submissions; Part II: Includes 22 papers from the resources track which were accepted from 71 submissions; and 21 papers in the in-use track, which had a total of 46 submissions.

The Reasoning Web summer school series is a well-established event, attracting experts from academia and industry as well as PhD students interested in fo- dational and applicational aspects of the Semantic Web. This volume contains thelecturenotesofthefourthsummerschool, which took place in Venice, Italy, in September 2008. This year, the school focussed on a number of important application domains, in which semantic web techniques have proved to be p- ticularly e?ective or promising in tackling problems. The ?rst three chapters provide introductory material to: - languages, formalisms, and standards adopted to encode semantic information; - "soft" extensions that might be useful in contexts such as multimedia or social network applications; - controlled natural language techniques to bring ontology authoring closer to end users. The remaining chapters cover major application areas such as social networks, semantic multimedia indexing and retrieval, bioinformatics, and semantic web services. Thepresentationshighlightedwhichtechniquesarealreadybeingsuccessfully applied for purposes such as improving the performance of information retrieval algorithms, enablingtheinteroperationofheterogeneousagents, modellinguser's pro?les and social relations, and standardizing and improving the accuracy of very large and dynamic scienti?c databases. Furthermore, the lectures pointed out which aspects are still waiting for a solution, andthepossiblerolethatsemantictechniquesmayplay, especiallythose reasoningmethodsthathavenotyetbeenexploitedtotheirfullpotential.Wehope thatthe school'smaterialwillinspire further exciting researchinthese areas. We are grateful to all the lecturers and their co-authors for their excellent contributions, to the Reasoning Web School Board, and Norbert Eisinger in particular, who helped in several critical phases, and to the organizations that supported this event: the University of Padua, the MOST project, and the N- work of Excellence REWERSE.