This book constitutes the refereed proceedings of the 20th International Conference on Architecture of Computing Systems, ARCS 2007, held in Zurich, Switzerland in March 2007.

The 20 revised full papers presented together with 1 invited paper were carefully reviewed and selected from 83 submissions. The papers cover a broad range of research topics related to basic technology, architecture, and application of computing systems with a strong focus on system aspects of pervasive computing and self organization techniques in both organic and autonomic computing.

This year marks the third edition of EuroSSC. It builds on the success of the past editions, held in Enschede, The Netherlands in 2006, and in Kendal, UK in 2007. On behalf of the Organizing Committee, we would like to welcome you to EuroSSC 2008, in Zurich, Switerland. This volume contains the invited papers and technical peer-reviewed papers selected for presentation at the conference. At EuroSSC we aim to explore technologies, algorithms, architectures, p- tocols, and user aspects underlying context-aware smart surroundings, coop- ating intelligent objects, and their applications. Since its inception, EuroSSC has taken a complementary technology-driven and user-driven view to discuss these aspects. It is one of the particularities of EuroSSC, and the 2008 edition made no exception. In addition we emphasized aspects related to quality of c- text and context-aware feedback by actuator systems. This re?ects the growing importance that context processing in uncertain environments and sensor and actuator networks take in ambient intelligence environments. We received 70 paper submissions. They originate from 30 countries of - rope, the Middle East and Africa (66%), Asia (22%), North America (9%), and South America (3%). These numbers re?ect the European origins of EuroSSC, but also show that EuroSSC is a recognized and attractive platform for parti- pants from all regions of the world.