[steveklabnik]

And copying from mine, regarding binary size:

So, https://github.com/polachok/fahrenheit is a toy executor that's trying to emulate tokio. It's still not really written for size; it assumes you have an OS, so it's also a bit bigger than you might do for true embedded. Its server example ends up being ~300k.

I also tried https://github.com/mgattozzi/async-await-class, which doesn't work with the OS, and is pretty basic. It's a bit outdated (` nightly-2018-08-18 `), also not written for size, but it ends up being ~155k.

Finally, https://github.com/Nemo157/embrio-rs is explicitly for embedded. Its "hello" example weighs in at ~38k.