Orome1 writes "Joanna Rutkowska, CEO of Invisible Things Lab, today released version 1.0 of Qubes, a stable and reasonably secure desktop OS. It is the most secure option among the existing desktop operating systems — even more secure than Apple's iOS, which puts each application into its own sandbox and does not count on the user to make security decisions. Qubes will offer users the option of using disposable virtual machines for executing tasks they believe could harm their computer. These VMs will be lightweight, easily and extremely speedily created and booted, and would be just as easy to discard."
First covered back in 2010
. See some screenshots
of the X11 part in action (and they say displaying clients from multiple "hosts" isn't useful...)