Tux Paint is a simple and entertaining drawing program geared towards young children. It has a simple interface, sound effects, and a cartoon character (Tux, the Linux penguin). Along with drawing brush strokes, lines and shapes, you can also enter text and place "rubber stamp" (or "sticker") images on the picture. Tux Paint is extensible, and could be useful in an educational environment (such as a grammar, elementary, or grade school). It's portable across numerous platforms, and runs well even on slower systems like the Pentium 133MHz.
Hasciicam makes it possible to have live ASCII video on the Web. It captures video from a TV card and renders it into ASCII, formatting the output into an HTML page with a refresh tag or in a live ASCII window or in a simple text file as well, giving anyone that has a bttv card, a Linux box, and a cheap modem line the ability to show a live asciivideo feed that can be browsable without any need for a plugin, Java, etc.
Tiled is a general purpose tile map editor. It's built to be easy to use, yet it is capable of catering to a host of varying game engines, whether your game is an RPG, platformer, or Breakout clone. Tiled supports plugins to read and write map formats other than its own map format.
Audiality is a highly scalable and portable audio engine and synthesizer. MIDI files are used in combination with scripting and modular synthesis, to minimize file sizes and maximize flexibility. Audiality can be used as a music and sound effects player in multimedia productions, or as a realtime MIDI synthesizer.
tkscript is a JIT-accelerated C-like scripting language with bindings for OpenGL, SDL, SDL_net, libpng, and zlib. A plugin SDK can be used to dynamically extend the script engine with custom C functions and C++ classes. It can be used to create portable, 3D, OpenGL-accelerated multimedia applications.
The TOXTOX browser is a Mozilla-based browser for your television. Packed with features, it will provide a real multimedia experience for your bedroom or living room while its controls remain easy and accessible with a keyboard or a remote control. With built-in support for Jabber/XMPP, it will be a platform for new and innovative social and interactive media. It can be customized by installing user-contributed addons and themes.