The new edition of this book presents a comprehensive and up-to-date description of the most effective methods in continuous optimization. Its publication responds to the growing interest in optimization in engineering, science, and business by focusing on the methods that are best suited to practical problems. This new edition has been thoroughly updated throughout. There are new chapters on nonlinear interior methods and derivative-free methods for optimization, both of which are widely used in practice and are the focus of much current research. Because of the emphasis on practical methods, as well as the extensive illustrations and exercises, the book is accessible to a wide audience including graduate students, researchers and practitioners. The authors have produced a text that is pleasant to read, informative and rigorous. It reveals both the beautiful nature of the discipline and its practical side.