Blasts from the Past
Before the year 2000 or so, the music was created on a Casio keyboard, a PAIA keyboard, and/or a Sequential Circuits Max synthesizer sequenced with Voyetra MIDI software.
After that, it was almost exclusively created with MIDImage 2 (or its predecessor, The Loxound Musical Pixelator), with occasional adventures with Lars Kindermann's Musinum or the Quasi Fractal Composer by Paul Whalley.