Eleven Windows 95 and 98 screensavers (Mystify, 3D Pipes, 3D Maze and eight more) rebuilt as an FFGL source and a matching mask effect. Every saver is a pure function of time and a seed, so nothing drifts with the frame rate, and you can scrub the whole thing and lock it to the beat.
This demo runs the plugin's shaders in your browser, so it needs JavaScript and WebGL2. The plugin itself, its source and its downloads are on its project page.