Goodgoat Linux is a simple to use Linux distribution that can be run from a USB drive, hard drive, or CD-ROM. Rather than overwhelming users with a multitude of applications, it aims to have the best utility for each job. In addition to including the latest software, it makes it easy to share a computer's hard drive over a network.
JoyWM (formerly known as Linux Multimedia System or LMMS) is a multimedia GUI written in Python/Pygame. It provides an easy-to-use GUI for tasks such as listening to music, watching movies, viewing pictures, and playing some games. It is appropriate for use on a TV and can be controlled with a joystick (or a keyboard if no joystick is present).
Style is the ongoing C++ port of IBM's SWT for Java, itself deriving from IBM's VisualAge for SmallTalk, with two major twists. First, it is written in 100% ISO-C++ with no specific compiler dependencies, and second, it comes with a threading model design that guarantee that users won't be stuck with busy cursors forever. It currently targets OS X, Win32, and GTK.
Stem Desktop is a minimalistic Debian desktop for low-end hardware with limited memory (166Mhz / less than 64M). The goal is to find programs that have the smallest possible memory footprint. After installing *.deb packages on top of clean Debian, the desktop is ready to accept graphical logins.