GNUSTEP Live CD contains a lot of software for GNUstep, a free implementation of the OPENSTEP framework (which is also directly used in Mac OS X as Cocoa). It includes excellent applications for RAD (GORM and ProjectCenter). The CD is available for i486, AMD64, Apple Mac PowerPC, and Sun UltraSPARC computers.
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.
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.
myOS is a minimalistic, OpenGL capable, GNU/Linux-based system without X. It is a bare bones Linux system, stripped of everything but the files necessary to compile and run OpenGL/C code. It has a simplified directory structure and a cleaned-up internal cross referencing. It has two available variants. myOSx-less fits within a 64 MB RAM disk and features a WebKit based on Trolltech's Qtopia demo Web browser. myOSx is oriented for X11, and its development tools are built around Trolltech Qtopia to produce applications based on the WebKit and for the framebuffer of the original myOS system.
iloog is a Gentoo-based live CD targeted mainly at students and scientists. It features UnionFS filesystem support that enables you to write everywhere on the LiveCD and install extra packages, a graphical X environment through the Fluxbox window manager, many programming editors and IDEs, and a plethora of scientific applications, including Octave, Namd, Merlin, and full (La)TeX support.
GoblinX XFlash is an edition specially designed for 1GB USB pen drives. The system differs from MegaFlash because it includes GoblinX Mini 2.7 instead of the Premium edition, plus applications used to compile other programs from source code, several more applications for everyday use, some bindings and languages, games, and OpenOffice.org.