From the article:

Many programming languages now provide the async/await keywords for expressing concurrency. The design rationale is pretty consistent: to make concurrent programs look more like straight-line code (see: Python, Rust, or Swift). We therefore describe the paradigm which encompasses async/await as straight-line asynchrony, as opposed to using event loops or callbacks.

Language designs for straight-line asynchrony have been brewing for over 15 years. In this project, we wanted to understand: how similar or different is async/await between languages? The short answer is a lot more different than we expected. We wrote a paper, “A Design Space Exploration of Async/Await”, to explain how.