You probably already have it. If you have Rails as a gem, try running gem_server and then opening http://localhost:8808/
You can generate your own rdoc with: rake doc:rails
I tend to do this so each project has a copy of the doc appropriate for the version of Rails that it is using.
-Rob
Rob Biedenharn http://agileconsultingllc.com Rob@AgileConsultingLLC.com