Qubes OS
A reasonably secure operating system
Qubes OS is a security and privacy-focused free and open source operating system that provides a safe platform for communication and information management.
Its architecture is built to enable a user to define different security environments on their computer and visually manage their interaction with each other, integrating their favorite applications from Debian, Fedora, and even Windows. Its robust control of networking enables the user to define the networking status of any domain or application, from airgapped/non-networked to routing through VPNs or the Tor anonymity network thanks to built-in Whonix integration.
From network-level protections to software-level protections, as well as protections against firmware and physical attacks, Qubes OS is trying to protect the user from the most significant attacks they can encounter, so that they can get their work done, safely.