SyncWall is quite a basic wallpaper changer with a special feature, it is the ability
to synchronize wallpaper change 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.
Because SyncWall is written with Qt, SyncWall runs on Windows and Linux (MacOSX isn't tested yet).
WallChange is a FREE to download open source program. It's a simple, program that will constantly change your wallpaper for you, to your settings. It supports almost all image types, has high customization with many features.