Dictionary.net

A program with the same approximate purpose as akaleidoscope: to make pretty pictures. Famous display hacksinclude munching squares, smoking clover, the BSD Unix"rain(6)" program, "worms(6)" on miscellaneous Unixes, and theX "kaleid(1)" program. Display hacks can also beimplemented without programming by creating text filescontaining numerous escape sequences for interpretation by avideo terminal; one notable example displayed, on any VT100, aChristmas tree with twinkling lights and a toy train circlingits base. The hack value of a display hack is proportionalto the aesthetic value of the images times the cleverness ofthe algorithm divided by the size of the code. Synonympsychedelicware.