Qubes OS – Qubes OS is a security-focused desktop operating system that aims to provide security through isolation.[6] Virtualization is performed by Xen, and user environments can be based on Fedora, Debian, Whonix, and Microsoft Windows, among other operating systems.[7][8]

On February 16, 2014, Qubes was selected as a finalist of Access Innovation Prize 2014 for Endpoint Security Solution.[9] Ultimately, the prize was awarded to Tails, another security-focused operating system, with Qubes and Open Whisper Systems being named runners-up.

Qubes OS – Wikipedia

https://en.wikipedia.org/wiki/Qubes_OS