display hack

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}.