This book constitutes the refereed proceedings of the 19th International Conference on Architecture of Computing Systems, ARCS 2006, held in March 2006. The 32 revised full papers presented together with two invited and keynote papers were carefully reviewed and selected from 174 submissions. The papers are organized in topical sections on pervasive computing, memory systems, architectures, multiprocessing, energy efficient design, power awareness, network protocols, security, and distributed networks