[unhammer]

> Wasn't there a Linux project where they could update the OS / kernel without a restart?

Ubuntu? Last time I updated, they asked me if I wanted to start using Livepatch, so it seems pretty integrated: https://ubuntu.com/security/livepatch

(though I'm horrible at noticing the critical battery warnings so I get frequent reboots for free – but that method wouldn't work on Windows which installs updates on shutdown!)