Hardened Debian improves Debian GNU/Linux with high security and hardening features, hardened kernels and packages, DHKP, and other security related enhancements. It makes systems more difficult to compromise using common attacks such as race conditions, chroot jail escapes, and buffer overflows.
OpenWrt is a Linux distribution for wireless routers. Instead of trying to cram every possible feature into one firmware, it provides only a minimal firmware with support for add-on packages. For users, this means the ability to custom-tune features, removing unwanted packages to make room for other packages. For developers, it means being able to focus on packages without having to test and release an entire firmware.
The submount removable media handling system automatically mounts and unmounts removable media devices such as CDROMs, DVDs, and floppy drives. It is a two part system, with a small kernel module and a userspace program. It provides the same functionality as supermount, but (hopefully) avoids supermount's stability problems.
The Project Akita OS (Orange OS) was started with the intent to design a lightweight operating system. It contains a small kernel designed for those interested in the low-level, practical aspects of building an x86 system. The host development environment is designed to work around the Bochs x86 emulator, so that you can easily test changes to the kernel.
Ficl (Forth inspired command language) is an ANS Forth interpreter written in C. Unlike traditional Forths, this interpreter is designed to be embedded into other systems as a command/macro/development prototype language. Ficl provides object extensions that can be used to wrap methods and structures of the host system without altering them.