Geex!

Fabricio Rocha's Geex! OS, where the philosophy is to make an OS with a very small footprint, working on old computers, and completely free. The project is still in the process of starting, and no code has been written yet. However, the site has a lot of interesting documentation on OSes in general. Documentation on Geex! itself is still sparse and sketchy, but there are beginnings of several proposals.