Unix Kernel Programming - Notes, source and links for Unix developers. Including ANCIENT Unix.
ARM Information - Specs and notes for ARM processors.
IsForth - a guy I know wrote this nice FORTH environment that I like.
GLFW - a free OpenGL FrameWork that I find very useful.
GLee - GL Easy Extension library. gives seamless access to nearly all OpenGL extensions.
GLEW - GL Extension Wrangler library - extension loading program for all your OpenGL needs.
pcc - Portable C Compiler. A free compiler written in the 1970's that has been updated with modern features and is actively developed as an alternative to other open source compilers.