Comment by pjc50
3 months ago
Possibly the nearest to applying capabilities to C is pointer authentication: https://lwn.net/Articles/718888/
(This is one of those times where the C memory model as described in the spec is very different from the mental PDP-11 that C programmers actually use to reason about)
CheriBSD is definitely closer: https://www.cheribsd.org/. Or one of the other CHERI projects.
C's file descriptors are capabilities.