Qubes is an open source operating system designed to provide strong security for desktop computing. Qubes is based on Xen, X Window System, and Linux, and can run most Linux applications and utilize most of the Linux drivers. In the future it might also run Windows apps.
Homepage: http://www.qubes-os.org/ Project wiki (with installation instruction): http://wiki.qubes-os.org/
Please remember to verify the digital signature with the keys provided at the normal download page! http://wiki.qubes-os.org/trac/wiki/QubesDownloads