This book attempts to convey to the reader that semiclassical physics can be fun, as well as useful for understanding quantum fluctuations in interacting many-body systems. It presents applications to finite fermion systems in diverse areas of physics.Editors Foreword -- Preface to the Paperback Edition -- Preface -- Introduction -- Quantization of integrable systems -- The single-particle level density -- The extended Thomas-Fermi model -- Gutzwillers trace formula for isolated orbits -- Extensions of the Gutzwiller theory -- Quantization of nonintegrable systems -- Shells and periodic orbits in finite fermion systems -- Concluding remarks -- The self-consistent mean field approach -- Inverse Laplace transforms -- More about the monodromy matrix -- Calculation of Maslov indices for isolated orbits