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! 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. This separation from the X11 environment means that an application, like skype or bluejeans, cannot share this screen.