Are any large enterprises using Heroku?

I'm interested as sometimes I get friends who are developers telling me about their Ruby deployments, and most of t开发者_运维百科hem are in large enterprises which are using Java mainly, but have some small projects in Ruby on Rails.

Have a look at the success stories page on heroku.com.

Since you are not asking a very specific question, I also want to point out that your friends could deploy their Rails stuff to JBoss with Torquebox.