This is a one-hour video recording of the presentation of Sean Bechhofer at the KnowledgeWeb summer school 2007. It comprises the video synchronized with the slides (requires Flash) or the video alone (Flash format).

Table of Contents: Ontology Languages for the Semantic Web The Semantic Web Vision What is the Problem? A Semantic Web ? First Steps Technologies for the Semantic Web Building a Semantic Web Languages Object Oriented Models Structure of an Ontology Ontology Languages Why Semantics? Formal Languages RDF The RDF Data Model Linking Statements RDF Syntax What does RDF give us? RDF(S): RDF Schema RDF(S) Examples RDF/RDF(S) ?Liberality? RDF/RDF(S) Semantics RDF(S) Inference What does RDF(S) give us? Problems with RDF(S) Solution The OWL Family Tree A Brief History of OWL Aside: Description Logics A Brief History of DLs DL Semantics OWL Layering OWL Full OWL DL OWL Lite OWL Syntaxes OWL Class Constructors OWL Axioms OWL Individual Axioms OWL Property Axioms Semantics Reasoning Instance Reasoning Why Reasoning? Example Necessary and Sufficient Conditions Example Common Misconceptions Disjointness Domain and Range And/Or and Quantification Closed and Open Worlds Extensions Rules Different Semantics null Extensions: OWL1.1 Extensions: OWL 1.1 OWL1.1: Role Axioms OWL1.1: Metamodelling OWL1.1: Fragments Extensions: Query and Retrieval Query Languages SPARQL SPARQL for OWL Lightweight Vocabularies Concept Schemes SKOS: Simple Knowledge Organisation System SKOS Example SKOS Use Cases Tools Summary Acknowledgements Thank you!