The book discusses the main issues of coordination in complex sociotechnical systems, covering distributed, self-organising, and pervasive systems. A chemistry-inspired model of coordination, a situated architecture and coordination language, and a cognitive model of interaction are the ingredients of the Molecules of Knowledge (MoK) model for self-organisation of knowledge presented in this book. The MoK technology is discussed, along with some case studies in the fields of collaborative systems, academic research, and citizen journalism. The target audience includes researchers and practitioners in the field of complex software systems engineering. The book is also appropriate for graduate and late undergraduate students in computer science and engineering.