Fortunately for Rust it's very easy to use a simple subset of the language. Lots of tough borrowing issues don't show up if you stick to the stack, and you can

Fortunately for Rust it's very easy to use a simple subset of the language. Lots of tough borrowing issues don't show up if you stick to the stack, and you can get very far with just the stack and some heap allocated vectors and maps. Not everybody needs to implement an async runtime.