1. The main loop of an event-processing
program; the code that gets commands and dispatches them for
execution. 2. [techspeak] In `device driver', code designed to
handle a particular peripheral device such as a magnetic disk or
tape unit. 3. In the TeX world and the computerized typesetting
world in general, a program that translates some device-independent
or other common format to something a real device can actually
understand.