Also, in terms of networking, if your doing blocking IO, the stdlib is fine. Otherwise, from my experience, I really like https://tokio.rs/ for non-blocking (I know people are torn on this one) and have used it in my DNS impl, https://github.com/bluejekyll/trust-dns
https://rocket.rs/, https://rusoto.github.io/rusoto/rusoto_core/index.html, https://docs.rs/postgres/0.15.1/postgres/, https://docs.rs/kafka/0.7.0/kafka/, https://docs.rs/reqwest/0.8.1/reqwest/, as well as many other supporting libraries. I've not run into many things where there isn't already support.
Also, in terms of networking, if your doing blocking IO, the stdlib is fine. Otherwise, from my experience, I really like https://tokio.rs/ for non-blocking (I know people are torn on this one) and have used it in my DNS impl, https://github.com/bluejekyll/trust-dns
For more info on web and Rust, this is a great page: http://www.arewewebyet.org/