There is some content there, for sure. I used gotapi instead of api.rubyonrails.org most of the time (they have other stuff there too, of course, which is handy). I have since switched to just looking stuff up in the source because I'm pretty familiar with it.
But I tried putting api.rubyonrails.org and apparently that also falls under the rubyonrails.org domain which I use quite a bit for rails dev.