Is anyone actually using Rust in production? There's a lot of excitement around it in the HN echo chamber, but I'm not sure how far that translates to real world use.

Since it's not very stable yet, production use is actively discouraged. I do know Tilde is using Rust for Skylight (http://skylight.io), but I don't know how far from production they are.

Skylight itself is still not quite out of beta, but iirc ever since reimplementing their monitoring and instrumentation in Rust they've been allowing their paying customers to opt into it (with the alternative being to stick with the older Ruby-based implementation).

For another company currently using Rust despite our frequent warnings, see OpenDNS: http://www.opendns.com/