woothee-rust 
The Rust implementation of Project Woothee, which is multi-language user-agent strings parsers.
Usage
parsing user-agent.
extern crate woothee;
use woothee::parse;
fn main() {
let result = parse("Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.1; Trident/4.0)");
println!("{:?}", result);
}
run
Some(WootheeResult { name: "Internet Explorer", category: "pc", os: "Windows 7", os_version: "NT 6.1", browser_type: "UNKNOWN", version: "8.0", vendor: "Microsoft" })
Benchmark
running 2 tests
test bench_uap ... bench: 204,584,510 ns/iter (+/- 4,739,819)
test bench_woothee ... bench: 542,426 ns/iter (+/- 24,330)
test result: ok. 0 passed; 0 failed; 0 ignored; 2 measured