This book is the second of two volumes that together give a comprehensive introduction to the theory of cooperative behavior in active systems. This volume is devoted to the properties of the complex chaotic patterns that can arise in distributed active systems. The reader will encounter strange attractors, fractals, discrete maps, spatio-temporal chaos etc., and will learn how these phenomena relate to the emergence of complex and chaotic patterns. Examples treated in detail include population explosion and extinction in fluctuating distributed media, and fluctuation effects in binary annihilation. This second edition has been revised and enlarged, in particular with respect to turbulence in distributed active systems, and a new section on control of chaotic behavior has been added. Much new material has been included in chapters where noise-induced pattern formation is considered.