This book deals with electrical, electrochemical, structural, magnetic, optical and lattice dynamical properties of conjugated polymers such as polyaniline, polyacetylene, polydiacetylene, polypyrrole, polyparaphenylene and polythiophene. Several new conjugated systems and model polyenes are also considered. Since the previous winter school on this topic held in 1985, the focus of interest in the field has broadened and now covers not only conductivity and relaxation phenomena of polyacetylene but also nonlinear optical properties, highly oriented and single crystal polymers, and electrochemical and opto-electrochemical properties of special materials. Particular attention is paid in this volume to the possible applications of these systems, for example, in electrochemical cells as electrode materials and in nonlinear optics devices, which now appear to be much more realistic than previously. The detailed contributions are complemented by short reviews of thin film polymers (Langmuir-Blodgett layers), filled polymers, ferromagnetic polymers, superconducting low-dimensional systems (including organic superconductors and high-temperature superconductors) and the application of fractal models to polymers.