The Center for Astronomical Adaptive Optics (CAAO) is a facility of Steward Observatory which is itself within the Department of Astronomy of the University of Arizona. The CAAO was founded in 1993. Its mission is to develop state-of-the-art adaptive optics systems for imaging and spectrometry at near infrared wavelengths. These systems will form an integral part of the various large telescopes under development by Steward Observatory, including the 6.5-meter conversion of the Multiple Mirror Telescope, the Large Binocular Telescope, and the southern hemisphere Magellan Telescope. An important technique being developed at the CAAO is nulling interferometry, which will be applied to the direct imaging of exoplanets and circumstellar dust disks.