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.