This volume of the Lecture Notes in Computer Science series contains all papers accepted for presentation at the 20th IFIP/IEEE International Workshop on Distributed Systems: Operations and Management (DSOM 2009), which was held in Venice, Italy, during October 27-28, 2009. DSOM 2009 was the 20th event in a series of annual workshops. It followed in the footsteps of previous successful meetings, the most recent of which were held on Samos, Greece (DSOM 2008), San Jos e, California, USA (DSOM 2007), Dublin, Ireland (DSOM 2006), Barcelona, Spain (DSOM 2005), and Davis, C- ifornia, USA (DSOM 2004). The goal of the DSOM workshops is to bring - gether researchersfromindustry andacademia workingin the areasofnetworks, systems, and service management, to discuss recent advances and foster future growth. In contrast to the larger management conferences, such as IM (Inter- tional Symposium on Integrated Network Management) and NOMS (Network OperationsandManagementSymposium),DSOMworkshopshaveasingle-track program in order to stimulate more intense interaction among participants.

This book constitutes the proceedings of the 8th International Conference on Web Information Systems Engineering, WISE 2007, held in Nancy, France, in December 2007.

The 40 revised full papers and 18 revised short papers presented were carefully reviewed and selected from about 200 submissions. The papers are organized in topical sections on querying, trust, caching and distribution, interfaces, events and information filtering, data extraction, transformation, and matching, ontologies, rewriting, routing, and personalisation, agents and mining, QOS and management, modeling, and topics.