The Free-POSIX Common Desktop Project exists to create an open standard for free Desktop implementations.
RTS game engine contributions to Stratagus. RPG mode, first-person mode, underground areas and more are planned. A distribution of Stratagus with the contributions compiled in will also be released here.
Crosos is a SubLinux Distribution
Crosos is a open-source OS. It is based on the Linux Kernel and mostly uses the same code in Ubuntu (but it has been derived from Debian)