This book has been prepared as a tribute to Prof. Alberto Isidori on the occasion of his 65th birthday. The book contains 27 chapters written by a number of researchers who have been involved, in different ways, in the prolific and high-impact career of Prof. Isidori. The chapters cover a significant number of control and systems theory topics and describe a mix of new methodological results, advanced applications, emerging control areas and tutorial works. The overall contributions have been divided in six parts: 'System Analysis', 'Optimization Methods', 'Feedback Design', 'Regulation', 'Geometric Methods' and 'Asymptotic Analysis'. All these fields reflect areas in which Prof. Isidori, during his scientific activity, has been actively involved by providing key ideas and pioneering contributions. The book is expected to be of significant interest to academic and industrial researchers involved in the area of linear and nonlinear control systems and a key reference for future research developments.