From George Hara:
Wallperizer is automatically changing your desktop wallpaper. You can add up to 100 directories where the program would look for pictures which would be used as wallpapers. The wallpaper can be changed automatically, either in order or randomly. Brightness normalization is an automatic process where bright pictures are made darker and dark pictures are made brighter, which can be used to bring the brightness of wallpapers close to the environmental light. A calendar can be displayed on the wallpaper. Calendars have skins. You can edit, load, and save calendar skins.