Distributed and Parallel Systems: From Cluster to Grid Computing, is an edited volume based on DAPSYS 2006, the 6th Austrian-Hungarian Workshop on Distributed and Parallel Systems, which is dedicated to all aspects of distributed and parallel computing. The workshop was held in conjunction with the 2nd Austrian Grid Symposium in Innsbruck, Austria in September 2006. This book is designed for a professional audience composed of practitioners and researchers in industry. It is also suitable for advanced-level students in computer science.