Hey @gidzr, some good questions here, let me try to clarify.

The default loop was introduced back in 2021 specifically to make async code easier to write and not get in your way, see release notes (https://github.com/reactphp/event-loop/releases/tag/v1.2.0) and the announcement blog post (https://clue.engineering/2021/announcing-reactphp-default-loop) for more background. On the code level, it's a simple static class that forwards all method calls to a single loop instance, simply facing the fact that there can only ever be a single loop realistically.

The new Async component was introduced in 2022 to make async code much easier to write and look just like synchronous code using async() and await() semantics, see release notes (https://github.com/reactphp/async/releases/tag/v4.0.0) and the announcement blog post (https://clue.engineering/2022/announcing-reactphp-async) for more background. On the code level, this means you can now use synchronous types and will no longer have to work with asynchronous concepts such as promises unless you want to. It will take advantage of the new Fiber class in PHP 8.1+ when available automatically, so you wouldn't ever have to interface with Fiber instances in your code.

Looking forward, we've announced our plans for ReactPHP v3 in late 2022 and have continued working on this vision ever since, see announcement (https://github.com/orgs/reactphp/discussions/481) for more background. ReactPHP v3 will take advantage of the above improvements automatically and will make writing async PHP much easier, noticeably faster and more awesome than ever. This is a massive effort, and while the development is seeing some steady progress, we're still actively looking for more sponsors to achieve these goals faster.

As you can see, all pure PHP, no magic involved 🪄

I hope this helps! 👍 If so, consider supporting this project, for example by becoming a sponsor ❤️