Tokio
A runtime for writing reliable asynchronous applications with Rust
...At a high level, Tokio provides a number of components needed for building asynchronous applications. These include a multithreaded, work-stealing based task scheduler; a reactor that's supported by the operating system's event queue; and asynchronous TCP and UDP sockets.
Tokio is reliable in that its APIs are memory-safe, thread-safe, and misuse-resistant. Thanks to its task scheduler, it is also incredibly fast. It is capable of processing hundreds of thousands of requests per second with little to no overhead.