Book excerpt: In this book, the authors review important developments and discuss new strategies for the performance evaluation of parallel, distributed and emergent systems. The purpose is to make analytical, simulation and testbed-based modelling and evaluation tools and methodology possible and understandable to a wider audience and to report the state-of-the-art innovative tools and techniques for system performance evaluation. Consequently, this book can serve as a valuable source of reference and indispensable reading for researchers, educators, engineers, graduate students, and practitioners in the field of design and analysis of such systems.