a collection offree screen saversfor X11, macOS,iOS and Androidby Jamie Zawinski and many others.

XScreenSaver is the standard screen saver collection shipped on most Linux and Unix systems running the X11 Window System. I released the first version in 1992. I ported it to macOS in 2006, to iOS in 2012, and to Android in 2014.

On X11 systems, XScreenSaver is two things: it is both a large collection of screen savers; and it is also the framework for blanking and locking the screen.

On macOS systems, these screen savers work with the usual macOS screen saving framework (X11 is not required).

On iOS devices, it is an application that lets you run each of the demo modes manually.

On Android, the savers work as both Daydreams and as Live Wallpapers.