VFeedback simulates the effect (likely unknown to da yoot of today) of pointing a video camera at an analog television. If you position things just right you can get seething flame spirals. The screen savers does an... adequate... job of this, by randomly zooming and rotating the camera, but it works a lot better when run interactively. Try to get a hard light/dark division kind of near the center of the screen and hold it there.
Running it in a window on Linux, left button pans, other buttons or modifiers rotate. There are also a bunch of keystrokes for twisting the tv knobs. On mobile, you can only pan, because the X11 code can't see multi-touch.
FilmLeader displays a looping countdown based on the SMPTE Universal Film leader, and it never reaches the end, which I am told is super frustrating.
GlitchPEG is perhaps the first screen saver that's excellent at detecting buffer overflow exploits. It loads an image, corrupts it, and then displays the corrupted version, several times a second. It glitches the image by altering random bytes in the compressed image file before de-compressing it. So if this saver crashes, congratulations, you have an exploitable image library!
It looks cool on JPEGs, but doesn't work well on PNG files, since PNG contains checksums that detect simple corruption.
GlitchPEG only works on X11 and MacOS, not iOS and Android, because right now there's no easy access to the un-decoded image data on the mobile platforms. I could add an API for that, but I haven't bothered.
I've already written about the new version of DymaxionMap, but now you can actually run it. It blends day and night maps into a single image that shows what the day/night terminator would look like moving across Flatland. It sort of feels like two spirals turning on opposite directions.
GLPlanet also looks a lot better now, since it also blends the day and night images with a dusk terminator instead of a hard edge.
Also, many more modes have been enabled on Android.