The Submillimeter Array (SMA) is an 8-element radio interferometer located atop Mauna Kea in Hawaii. Operating at frequencies from 180 GHz to 900 GHz, the 6m dishes may be arranged into configurations with baselines as long as 500m, producing a synthesized beam of sub-arcsecond width. Each element can observe with two receivers simultaneously, with 2 GHz bandwidth each. The digital correlator backend allows flexible allocation of thousands of spectral channels to each receiver. The Submillimeter Array is a joint venture of the Smithsonian Astrophysical Observatory and the Academia Sinica Institute of Astronomy and Astrophysics.