Most of these late 1990s demos are QuickTime movies made with QTS (QuickTime Synthesizer) - a
2D rendering language I developed for generating animated procedural textures & abstract animations.
It was a follow up to my earlier programs Pixel Magic and Photoshop Expression, from the early 90s.
I am no longer developing QTS, doing most of my work these days using Perl scripts, ImageMagick and the Processing language.
A currently available plugin that is very similar in spirit to QTS is MathMap, developed independently by Mark Probst.