This book contains a collection of seven thoroughly revised tutorial papers based on lectures given by leading researchers at the 5th International Summer School on the Reasoning Web, held in Brixen-Bressanone, Italy, from August 30 to September 4, 2009. The objective of the book is to provide a coherent introduction to semantic web methods and research issues with a particular emphasis on reasoning. The focus of this year's event was on the use of semantic technologies to enhance data access on the web. Topics covered include design and analysis of reasoning procedures for description...