Comment Re:Real use (Score 3, Informative) 206
Here's a quick list just off the top of my head:
* YellowPages.com
* All of the 37signals apps (Basecamp, Campfire, etc.)
* Hulu
* Scribd
* LivingSocial
* Penny Arcade
* GitHub
* Twitter (backend powered by a ton of stuff but their frontend is mostly Rails)
* Chow.com
* Oracle.Mix
* Shopify
* Justin.tv
* Crunchbase
There are a ton more public facing and even more (as you mention) sort of "behind the firewall" type stuff. Ruby (especially Rails) has stepped up as a pretty major contender in the web development arena. :)