Projected input and output devices adapt to a desktop environment by sensing objects at the desktop environment and altering projected light in response to the sensed objects. For instance, projection of input and output devices is altered to limit illumination against and end user's hands or other objects disposed at a projection surface. End user hand positions and motions are detected to provide gesture support for adapting a projection work space, and configurations of projected devices are stored so that an end user can rapidly recreate a projected desktop. A projector scan adjusts to limit traces across inactive portions of the display surface and to increase traces at predetermined areas, such as video windows.