dragon [MIT] A program similar to a daemon, except that it is not invoked at all, but is instead used by the system to perform various secondary tasks. A typical example would be an accounting program, which keeps track of who is logged in, accumulates load-average statistics, etc. Under ITS, many terminals displayed a list of people logged in, where they were, what they were running, etc., along with some random picture (such as a unicorn, Snoopy or the Enterprise), which was generated by the "name dragon". Use is rare outside MIT, under Unix and most other operating systems this would be called a "background demon" or daemon. The best-known Unix example of a dragon is cron. At SAIL, they called this sort of thing a "phantom".
[Jargon File]
