From The Free On-line Dictionary of Computing (8 July 2008) [foldoc]:
driver
drivers
1. <operating system> device driver.
2. <programming> The main loop of an event-processing
program; the code that gets commands and dispatches them for
execution.
3. <tool> In the TeX world and the computerised typesetting
world in general, a program that translates some
device-independent or other common format to something a real
device can actually understand.
[Jargon File]