Principles of Distributed Systems : 7th International Conference OPODIS 2003 La Martinique French West Indies December 10 13 2003 Revised Selected Papers This book constitutes the thoroughly refereed post proceedings of the 7th International Conference on Principles of Distributed Systems OPODIS 2003 held at La Martinique French West Indies in December 2003. The 19 revised full papers presented together with abstracts of 3 invited talks were carefully selected from 61 submissions during two rounds of reviewing and improvement. The papers are organized in topical sections on distributed and multiprocessor algorithms; peer to peer systems and middleware; real time and embedded systems; and verification modeling and performance of distributed systems