There is a general tendency to move less-used or more experimental Application Programming Interfaces (APIs) out of the language and the standard library and into their own crates. An ever-growing ecosystem of crates for Rust is at your disposal at https://crates.io/, with over 2,000 crates in stock at the time of writing (May 2015).
At Awesome Rust (https://github.com/kud1ing/awesome-rust), you can find a curated list of Rust projects. This site only contains useful and stable projects and indicates whether they compile in the latest Rust version. In addition, it is worth to search Rust Kit (http://rustkit.io/), as well as the Rust-CI repository at http://www.rust-ci.org/projects/.
In general, it is advisable that you search for crates that are already available whenever you embark on a project that requires specific functionality. There is a good chance that a crate that conforms to your needs already exists, or perhaps, you can find some usable starting code upon which you can build what you exactly need.