"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.
image-deduplication-tool is a script designed to scan specified paths and calculate the DCT hashes of all the images there. It compares the hashes to find closest-looking image pairs, despite various alternations (such as crop, rotation, gamma/color correction, noise, etc.), optionally presenting them in a feh image viewer for the operator to easily compare and remove one of the versions. It uses libpHash to produce and compare perceptual hashes.
fifoirc creates a named pipe on the local filesystem, such that any data written to the pipe will be written to an IRC channel. It is also possible to connect a filter program to the channel, such that any text written in the channel is passed to the program, and any text output by the program is passed to the channel.
pulseaudio-mixer-cli is an interactive ncurses UI to control the volume of PulseAudio streams. It is somewhat like alsamixer, but focused not on sink volume levels (which can actually be controlled via alsamixer, with the alsa-pulse plugin), but rather on the volume of individual streams from applications, allowing the user to balance sound levels between them. Interaction with pulseaudio is done through the DBus interface, and the UI is designed to be as simple as possible, without heavy DE dependencies like GNOME libs or KDE/QT.
notification-thing is a full-featured implementation of the Desktop Notifications Specification. It is not tied to any specific desktop environment, and is focused on features like rate-limiting and flexible filtering to minimize distraction and noise ratio in a transparent way, without silently dropping anything ever.