This volume contains the tutorial papers of the Summer School "Reasoning Web,"July25-29,2005(http: //reasoningweb. org). TheSchoolwashostedbythe University of Malta and was organized by the Network of Excellence REWERSE "Reasoning on the Web with Rules and Semantics" (http: //rewerse. net), funded by the EU Commission and by the Swiss Federal O?ce for Edu- tion and Science within the 6th Framework Programme under the project ref- ence number 506779. The objective of the school was to provide an introduction into methods and issues of the Semantic Web, a major endeavor in current Web research,...