How Not to post a job posting.
pikimal.theresumator.com
pikimal.theresumator.com
I get to say "our guy" because I was the original author of the job post!
The way I read it is that you don't have to have experience in Ruby on Rails, you just have to be able to learn it quickly and be comfortable developing applications with it. As a seasoned .NET or Java developer, it might only take you a few weeks to adapt ("you can pick up a new language faster than your laundry"), even if you have never used Ruby on Rails before.
You have to be completely comfortable with:
* Developing Ruby on Rails applications
Now, technically they don't say you need to know Ruby, but I'd be rather surprised if you don't need experience in Ruby to be completely comfortable with developing Ruby on Rails applications.