SyncWall is a basic wallpaper changer with a special feature, the ability to synchronize wallpaper changes between several workstations with a basic (and unsecured) client/server protocol. Each workstation must share the same pool of files, there is no FTP or Internet download. Other interesting features are simple multi-monitor support and the ability to add special effects to wallpaper.
WallShuffle allows you to regularly change your wallpaper. You select a folder, then select a duration to apply a random picture as a desktop background. You can start the program in minimized mode with the "-m" argument, if you don't want to see it, or even hide the icon from the tray and forget it.
"aura" is a desktop (X root window) background setter. It picks images randomly from specified paths, skipping those that are too small or have inappropriate aspect ratios, and rescales them by cropping solid margins, resizing with cubic interpolation and then the liquid rescale algorithm to fit the desktop with as little quality loss as possible. Images are labelled in the corner using embedded tags. It can changes images on a timed basis or when triggered by SIGHUP or the CLI, and tracks previous and blacklisted images.