[jungler]

I scrolled through https://github.com/dbohdan/embedded-scripting-languages

And there are some options. You could achieve barebones VM protections with Pawn(the language enforces very little otherwise, though). You could use something ref-counted like a TCL implementation, which would allow you to design around linear allocation times. The vast majority are using some kind of tracing collector of course, but I wouldn't say this is a total loss for achieving a combination of real time and memory protection.

[monocasa]

There 'embedded' means 'a library included as a subsystem in a larger application', not 'embedded systems'.

PAWN for instance is explicitly 32bit and interpreted, so would run dog slow on something like an Arduino.

Something refcounted like TCL implies tons of heap allocations, which implies fragmentation at the very small RAM sizes of a lot of these chips.