That sounds kind of like what I mean. I consider it having a runtime if anything that can be used without importing the standard library won't work out of the box when you boot a machine to it.
Well, the 'standard library' is a bit of a flexible concept in Rust. We have 'libcore' and 'libstd'. core is what's still usable without any runtime support whatsoever, and std does.
I mean, none of Rust's _features_ don't work without runtime support, but libraries that need tasks (threads) and task unwinding require the runtime. Those are all library features not language features.
Ah ok, interesting. I've been contemplating converting my toy kernel (which doesn't do all that much yet) into Rust, since it doesn't use a GC for everything, could be fun.