display hack
n. A program with the same approximate purpose as a
kaleidoscope: to make pretty pictures. Famous display hacks
include munching squares, smoking clover, the BSD UNIX
`rain(6)' program, `worms(6)' on miscellaneous UNIXes,
and the X `kaleid(1)' program. Display hacks can also be
implemented without programming by creating text files containing
numerous escape sequences for interpretation by a video terminal;
one notable example displayed, on any VT100, a Christmas tree with
twinkling lights and a toy train circling its base. The hack value
of a display hack is proportional to the esthetic value of
the images times the cleverness of the algorithm divided by the
size of the code. Syn. psychedelicware.