I suppose it depends on if we're talking about server-focused OSes or desktops - for the desktop, there's Qubes[1] and I think it would be fair to say ChromeOS[

I suppose it depends on if we're talking about server-focused OSes or desktops - for the desktop, there's Qubes[1] and I think it would be fair to say ChromeOS[2] should be mentioned... 1: https://www.qubes-os.org/ https://www.qubes-os.org/ 2: https://en.wikipedia.org/wiki/Chrome_OS#Security https://en.wikipedia.org/wiki/Chrome_OS#Security