Recent advancements in Lyapunov-based design and analysis techniques have applications to a broad class of engineering systems, including mechanical, electrical, robotic, aerospace, and underactuated systems. This book provides a practical yet rigorous development of nonlinear, Lyapunov-based tools and their use in the solution of control- theoretic problems; includes a wide range of applications, motivating examples, and new design techniques making it suitable for an extensive audience of graduate students, professional engineers, and researchers in control systems, robotics, and applied mathematics.