"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.
BackPlay a program that plays music files from a folder in the background. At login, it scans a directory called "BackPlay" under the user's Music directory, and begins playing any music files it finds there in random order. BackPlay is independent from iTunes. It can be paused from an icon in the status area.