ChBg is for changing desktop backgrounds in a given period. It can render images with 10 modes (such as tiled, centered, scaled, etc.). It uses Imlib1, Imlib2, or gdk_pixbuf for loading images, so it supports many image formats. ChBg has a windowed setup program, is able to load setup files, can be used as slideshow picture previewer in its own window or as a desktop background, and can be used as screensaver or as an xscreensaver hack. It has a dialog for fast previewing of pictures and very usable thumbnail previews.
Xautolock monitors console activity under the X window system, and fires up a program of your choice if nothing happens during a user configurable period of time. You can use this to automatically start up a screen locker in case you tend to forget to do so manually before having a coffee break.
Snow Path Formation Simulator is a program that models the process of people forming very distinct, and yet not always altogether logical looking, paths in the snow as they walk across open spaces. The evolving condition of the snow is displayed graphically. This project may eventually mature into a screensaver.
ColdSpot is a simple screen locker for X. When the mouse is left inside the transparent ColdSpot window, a user-specified program is kicked off to lock the screen. It is probably simplest to use with focus follows mouse or sloppy focus, although it should still work with click-to-focus.
BitLife is an implementation of life using boolean operations (AND, OR, XOR), computing each new cell from 9 bits (itself & neighbours). It's performed in parallel on the whole image by bitblit operations (with hardware accelearation where possible). This also allows many parallel life games to run in each bitplane of the screen, giving a translucent blending effect. A proof-of-concept Python (pygame/Numeric) implementation and an xscreensaver hack are included.