"I'm not aware of any other language that has concurrency constructs as elegant and easy to use as Rust's spawn, and I don't know of any language that comes close to the race-free safety guarantees provided by Rust."

I'd recommend having a look at Erlang, it allows you to start lightweight pseudo processes for concurrency and provides a robust data sharing model.

Not so sure about low level access, we used C for those parts in the OS course I took.