- Accessibility built in, eg the OS takes care of adapting to what the user can do ( vision, subtitles, adaptive keyboard input etc).

- trivially replaceable kernel, to encourage research and experimentation, real time use, etc.

- ruthless, consistent separation of user data, user configuration, and an unbreakable standard for where programs get installed. Just look at dotfiles, hier/LFS, the windows Registry etc to see what a mess this is.

- a native grid compute protocol that allowed any two or more computers to merge into a single system image and automatically distribute workloads across them. We have clustering and the insane complexity of k8s today but it imagine something as easy as "Bonjour and Plan 9"!