A broad account of the main characteristics of the OmegaCAM 16Kx16K detector system is given. Requirements and additional constraints, design strategy, implementation, and first laboratory results are described for the detector head, cooling system, temperature and shutter control. Synchronization of multiple controllers, and careful safety provisions are explained The system has already passed most acceptance tests and will soon he ready for shipment. Commissioning in Chile is foreseen in 2006.