NOTE: The setting described below have security implications. See https://groups.google.com/d/msg/qubes-users/3amtMOIBTgI/rXLXmbM5AAAJ for discussion. At the moment, I am not recommending this approach. I’ll update here if I am able to improve on it. Caveat emptor! UPDATE: See revised post. The Qubes operating system aims to be reasonably secure through isolation. One example of isolation: one Qubes virtual machine runs the windowing environment, while other VMs run applications displayed in that environment.