Making Grids Work includes selected articles from the CoreGRID Workshop on Grid Programming Models, Grid and P2P Systems Architecture, Grid Systems, Tools and Environments held at the Institute of Computer Science, Foundation for Research and Technology - Hellas in Crete, Greece, June 2007. This workshop brought together representatives of the academic and industrial communities performing Grid research in Europe. Organized within the context of the CoreGRID Network of Excellence, this workshop provided a forum for the presentation and exchange of views on the latest developments in Grid Technology research. This volume is the 7th in the series of CoreGRID books.