Abstract: A Modular Library System, compact disc holder comprises a main housing unit with a lower plate, an upper plate, a pair of opposing side walls, and a rear wall. In addition, the main housing includes an inner retractable plate. Mounted on the inner retractable plate is an inner unit, with a turntable in between, allowing for 180 degree rotation when the inner retractable plate is fully extended. Accordingly, the retractable inner unit is comprised of a lower plate, an upper plate, a pair of opposing side walls, and two inner walls parallel to the opposing side walls. Housed within the inner unit are six individual smaller units, which have a series of elongated ribs, providing storage slots for CD's. Each of these six individual smaller units can be removed and relocated as desired. The dimensions of the compact disc housing unit were designed to fit into the bottom of most stereo rack systems, although it may stand alone, as well.