-% Language FAQ
-
+% The Rust Language FAQ
## Are there any big programs written in it yet? I want to read big samples.
[github-rust]: https://github.com/trending?l=rust
+## Is anyone using Rust in production?
+
+Currently, Rust is still pre-1.0, and so we don't recommend that you use Rust
+in production unless you know exactly what you're getting into.
+
+That said, there are two production deployments of Rust that we're aware of:
+
+* [OpenDNS](http://labs.opendns.com/2013/10/04/zeromq-helping-us-block-malicious-domains/)
+* [Skylight](http://skylight.io)
+
+Let the fact that this is an easily countable number be a warning.
+
## Does it run on Windows?
Yes. All development happens in lock-step on all 3 target platforms. Using MinGW, not Cygwin. Note that the windows implementation currently has some limitations: in particular 64-bit build is [not fully supported yet][win64], and all executables created by rustc [depend on libgcc DLL at runtime][libgcc].
## Why aren't values type-parametric? Why only items?
-Doing so would make type inference much more complex, and require the implementation strategy of runtime parametrization.
+Doing so would make type inference much more complex, and require the implementation strategy of runtime parameterization.
## Why are enumerations nominal and closed?
`RUST_LOG=rustc::metadata::creader,rustc::util::filesearch,rustc::back::rpath`
For a full description see [the logging crate][1].
+## How fast is Rust?
+
+As always, this question is difficult to answer. There's still a lot of work to
+do on speed, and depending on what you're benchmarking, Rust has variable
+performance.
+
+That said, it is an explicit goal of Rust to be as fast as C++ for most things.
+Language decisions are made with performance in mind, and we want Rust to be as
+fast as possible. Given that Rust is built on top of LLVM, any performance
+improvements in it also help us be faster.
+
[1]:log/index.html