A conventional box coating chamber has been equipped with three dc magnetron sputtering cathodes, reactive gas (02, N2, H2) pressure and flow control, a planetary substrate holder, and optical monitoring to produce a low-temperature batch coating system for multilayer optical coating fabrication using oxides, nitrides, semi-conductors, and semitransparent metals. The system realizes the benefits traditionally derived from this geometry: maximum area of uniform coating thickness, spatially averaged coating flux impingement angles, and precise thickness monitoring. The use of sputtering cathodes adds the benefits of increased flexibility in choice of materials deposited, increased adatom energy at the substrate, and increased chemical reactivity in a gas discharge. Dense, durable, fully reacted dielectric coatings are achieved at low processing temperatures. Metal targets (sources) are used for ease of fabricatton, and dc power avoids radio frequency (rf) impedance matching requirements. In this paper, the chamber and components are described; operation of the cathodes is explained; and thickness uniformity profiles, deposition rates, and substrate temperature data are related. A list of materials investigated to date is presented with pertinent optical properties and intrinsic mechanical stress values. Illustrative performance examples for multilayer coatings on glasses and plastics are included.