Description:The study of Complex Systems is growing rapidly, and modelling and simulation tools are an important part of the process. This volume brings together work from a multidisciplinary group of scientists, from biology and computer science, who are studying a variety of techniques and applications for modelling and simulating complex systems. A common theme emerging from much of this work is an emphasis on validation: how one can have confidence that a computer simulation is saying something sensible about the complex real-world domain of interest.