Listaller unifies the way you manage software on your Linux system by providing a user-friendly, application-centered software manager GUI. It also provides a software setup package format (the IPK package format), which works on all Linux distributions, as well as tools to make your application binaries work on every Linux distribution. The project has merged with Autopackage some time ago. One of Listaller's strengths is its close integration with AppStream and PackageKit. This means that you will be able to manage Listaller-installed applications with your favorite package-manager, like GNOME-PackageKit, Apper, or even the Ubuntu Software Center. Listaller is primarily designed to be run on Linux distributions, but it could be ported to *BSD.
DeaDBeeF is an audio player for GNU/Linux and other UNIX-like systems. It is written in C with some plugins in C++. It has minimal dependencies, a native GTK2 GUI, cuesheet support, support for MP3, Ogg, FLAC, and APE, chiptune formats with subtunes, song-length databases, and more. It is very fast and lightweight, and extensible using plugins (DSP, GUI, output, input, etc.). The GUI looks similar to Foobar2000.
Privacy Manager for Zeitgeist is a graphical user interface which lets you easily control what gets logged by Zeitgeist. It supports setting up blacklists according to several criteria (such as application or file types), temporarily stopping all logging, and deleting recent events.