Nick Black has put together an extensive
guide to the io_uring API and the lib_uring user-space library.

It combines asynchronous I/O, system call polybatching, and
flexible buffer management, and is IMHO the most substantial
development in the Linux I/O model since Berkeley sockets (yes, I’m
aware Berkeley sockets preceded Linux. Let’s then say that they’re
the most substantial development in the UNIX I/O model to originate
in Linux)

Source: LWN.net – A guide to io_uring