catflap.org Online Dictionary Query

  demoeffect n. [{demoscene] What among hackers is called a display
     hack. Classical effects include "plasma" (colorful mess), "keftales"
     (x*x+y*y and other similar patterns, usually combined with
     color-cycling), realtime fractals, realtime 3d graphics, etc.
     Historically, demo effects have cheated as much as possible to gain more
     speed and more complexity, using low-precision math and masses of
     assembler code and building animation realtime are three common tricks,
     but use of special hardware to fake effects is a Good Thing on the
     demoscene (though this is becoming less common as platforms like the
     Amiga fade away).