You're linking to an old version of the rust documentation from before it was even 1.0.0. Rust used to have a runtime before 1.0.0 to implement green threading.

You're linking to an old version of the rust documentation from before it was even 1.0.0. Rust used to have a runtime before 1.0.0 to implement green threading. But this is not the case anymore. Rust can be entirely statically linked into a self-contained library that has no runtime requirements whatsoever.