Acidwarp is an early and influential example of
eye candy software. It was, in the early
1990s, a fun way to turn your
DOS PC into a pretty decoration, or a
trip toy. The images were generated with 40-odd mathemetical functions, and animated by colour-cyling them. At only 56Kb in size, it is not a large program, but that's all the better to take it to the party on a
floppy disk.
Acidwarp was written by Noah Spurrier and Mark Bilk. Acidwarp was always free of cost, and the source is also available these days. It's written in C. A linux version has been out since 1996, ported by Steven Wills. The video looks low-resolution and grainy by today's standards, but it still runs, in a DOS shell, under Windows XP.
Acidwarp is resident at http://www.noah.org/acidwarp/ There you'll also find instructions for building "The warper", a cheap and simple video projecter-type thing made from a cardboard box and a fresnel lens, so you can all sit and watch it. Far out, dude!