Qubes OS is a free and open-source, security-oriented operating system for single-user desktop computing. Qubes OS leverages Xen-based virtualization to allow for the creation and management of isolated compartments called qubes. These qubes, which are implemented as virtual machines (VMs). This allows each component of the operating system to be isolated from other pieces, preenting compromises from spreading or information from leaking.

https://www.qubes-os.org