This book contains a collection of chapters, each of which was contributed by experts in their respective topic. Some chapters focus on scientific results in the fields linked with complex systems, while other deal with methodologies for operating within complex systems and their researching. Since all, or at least a significant majority of our activities are linked to complex systems and are conducted while we are explicitly in a complex system, chapters of this book are both widely applicable to a variety of real life situations and applicable for initiating a specific research.