[avadodin]

Fil-C vs CHERI vs SeL4 vs YOLO

I think hardware protection is usually easier to sell but it isn't when it is slower or more expensive than the alternative.

[Joker_vD]

"Operating System Principles" (1973) by Per Brinch Hansen. A full microkernel OS (remake of RC-4000 from 1967) written in a concurrent dialect of Pascal, that also manages to make do without hardware protection support.