This book constitutes the refereed proceedings of the 8th International Semantic Web Conference, ISWC 2009, held in Chantilly, VA, USA, during October 25-29, 2009.

Research Track.- Queries to Hybrid MKNF Knowledge Bases through Oracular Tabling.- Automatically Constructing Semantic Web Services from Online Sources.- Exploiting User Feedback to Improve Semantic Web Service Discovery.- A Generic Approach for Large-Scale Ontological Reasoning in the Presence of Access Restrictions to the Ontology's Axioms.- OntoCase-Automatic Ontology Enrichment Based on Ontology Design Patterns.- Graph-Based Ontology Construction from Heterogenous Evidences.- DOGMA: A Disk-Oriented Graph Matching Algorithm for RDF Databases.- Semantically-Aided Business Process Modeling.- Task Oriented Evaluation of Module Extraction Techniques.- A Decomposition-Based Approach to Optimizing Conjunctive Query Answering in OWL DL.- Goal-Directed Module Extraction for Explaining OWL DL Entailments.- Analysis of a Real Online Social Network Using Semantic Web Frameworks.- Coloring RDF Triples to Capture Provenance.- TripleRank: Ranking Semantic Web Data by Tensor Decomposition.- What Four Million Mappings Can Tell You about Two Hundred Ontologies.- Modeling and Query Patterns for Process Retrieval in OWL.- Context and Domain Knowledge Enhanced Entity Spotting in Informal Text.- Using Naming Authority to Rank Data and Ontologies for Web Search.- Executing SPARQL Queries over the Web of Linked Data.- Dynamic Querying of Mass-Storage RDF Data with Rule-Based Entailment Regimes.- Decidable Order-Sorted Logic Programming for Ontologies and Rules with Argument Restructuring.- Semantic Web Service Composition in Social Environments.- XLWrap - Querying and Integrating Arbitrary Spreadsheets with SPARQL.- Optimizing QoS-Aware Semantic Web Service Composition.- Synthesizing Semantic Web Service Compositions with jMosel and Golog.- A Practical Approach for Scalable ConjunctiveQuery Answering on Acyclic Knowledge Base.- Learning Semantic Query Suggestions.- Investigating the Semantic Gap through Query Log Analysis.- Towards Lightweight and Robust Large Scale Emergent Knowledge Processing.- On Detecting High-Level Changes in RDF/S KBs.- Efficient Query Answering for OWL 2.- Multi Visualization and Dynamic Query for Effective Exploration of Semantic Data.- A Conflict-Based Operator for Mapping Revision.- Functions over RDF Language Elements.- Policy-Aware Content Reuse on the Web.- Exploiting Partial Information in Taxonomy Construction.- Actively Learning Ontology Matching via User Interaction.- Optimizing Web Service Composition While Enforcing Regulations.- A Weighted Approach to Partial Matching for Mobile Reasoning.- Scalable Distributed Reasoning Using MapReduce.- Discovering and Maintaining Links on the Web of Data.- Concept and Role Forgetting in Ontologies.- Parallel Materialization of the Finite RDFS Closure for Hundreds of Millions of Triples.- Semantic Web In Use.- Live Social Semantics.- RAPID: Enabling Scalable Ad-Hoc Analytics on the Semantic Web.- LinkedGeoData: Adding a Spatial Dimension to the Web of Data.- Enrichment and Ranking of the YouTube Tag Space and Integration with the Linked Data Cloud.- Produce and Consume Linked Data with Drupal!.- Extracting Enterprise Vocabularies Using Linked Open Data.- Reasoning about Resources and Hierarchical Tasks Using OWL and SWRL.- Using Hybrid Search and Query for E-discovery Identification.- Bridging the Gap between Linked Data and the Semantic Desktop.- Vocabulary Matching for Book Indexing Suggestion in Linked Libraries - A Prototype Implementation and Evaluation.- Semantic Web Technologies for the Integration of Learning Tools and Context-Aware Educational Services.-Semantic Enhancement for Enterprise Data Management.- Lifting Events in RDF from Interactions with Annotated Web Pages.- A Case Study in Integrating Multiple E-commerce Standards via Semantic Web Technology.- Supporting Multi-view User Ontology to Understand Company Value Chains.- Doctoral Consortium.- EXPRESS: EXPressing REstful Semantic Services Using Domain Ontologies.- A Lexical-Ontological Resource for Consumer Heathcare.- Semantic Web for Search.- Towards Agile Ontology Maintenance.- Ontologies for User Interface Integration.- Semantic Usage Policies for Web Services.- Ontology-Driven Generalization of Cartographic Representations by Aggregation and Dimensional Collapse.- Invited Talks.- Populating the Semantic Web by Macro-reading Internet Text.- Search 3.0: Present, Personal, Precise.