AllTray is a program you can use on UNIX and UNIX-like systems, such as GNU/Linux or FreeBSD, running the X Window System. It is used to “dock” application software into the system tray (also known as the “notification area”). AllTray aims to be standards-compliant and work with any desktop environment/window manager+system tray combination that is also standards-compliant.
radare2 aims to create a complete, portable, multi-architecture, Unix-like toolchain for reverse engineering. It is composed of a hexadecimal editor (radare) with a wrapped I/O layer supporting multiple backends for local/remote files, debugger (OS X, BSD, Linux, W32), stream analyzer, assembler/disassembler (rasm) for x86, ARM, PPC, m68k, Java, MSIL, and SPARC, code analysis modules, and scripting facilities. It also has a bindiffer named radiff, base converter (rax), a shellcode development helper (rasc), a binary information extractor supporting PE, Mach0, ELF, class, etc. named rabin, and a block-based hash utility called rahash. Radare was rewritten as radare2, and the old version is only maintained for bugfixes.
gtkaml is an XML syntax and parser that extends the Vala.Parser and transforms all your tags into a valid Gtk+ UI class. It features a casual XML syntax for describing the way Gtk widgets are laid out in a (new) custom widget you're creating. Code "islands" (written in Vala) are used for widget signal handling and other methods/signals/properties that you're introducing. It doesn't depend on an external library at run-time, and it is much more readable than the usual UI boilerplate.
Epris is a D-Bus service and command line client to listen to music. Unlike xmms2 or mpd, it uses GStreamer and D-Bus. It supports all formats supported by GStreamer, and can play both video and audio. It supports gap-less playback thanks to playbin2. It has an extensible command line interface, a small memory footprint, automatic deactivation, and an easy D-Bus interface for other UIs.
Sync Mail Dir is a set of utilities to synchronize a pair of mailboxes in Maildir format using SSH to transfer data. It provides the smd-pull utility to pull changes made on the remote mailbox, smd-push to propagate local changes to the remote mailbox, and smd-loop to iterate push and pull in a timely way. Unlike OfflineIMAP It requires no IMAP server to be installed on the remote host. Moreover, it never attempts to automatically resolve conflicts between incompatible mailbox statuses; it just notifies the user explaining how he can fix the problem. Its design is similar to that of Maildirsync, but it is more efficient in terms of CPU cycles and disk I/O.
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.
Ejecter is a little tool that makes it possible to unmount external devices and eject CD-ROMs without having to right-click on the device icon (either on the desktop or in Nautilus). It sits in the background and shows an icon in the system tray when one or more peripherals are connected to your PC: once clicked, a window appears with the list of the devices (volume name and device type, and much clearer than the similar thing available on Windows) and the related eject button. Being written in Vala, it is translated into C code and then compiled. This means that it's lightweight and consumes little memory, does not require a full VM like Python, and has no strange requirements to run (just GLib/GTK).