What is the latest stable Rails version?
What is the latest stable version of rails? I want to install rails 3.1 but I see there is 3.1.3 now, what is the difference? What ruby version is it most compatible with?
I recommend to always check on GitHub via the "branches" menu what the latest version is on each branch. You can see the latest version easily by checking the contents of the RAILS_VERSION file
If you already have a Rails App in production, I would highly recommend: don't just blindly take the latest version just because it just came out -- there were many cases in the past where a new version introduced incompatibilities or new bugs which were serious enough to have to wait for a fix before the features in the Rails release were really usable. I know a couple of people who have Production sites and still run 3.0.11 or lower, rather than 3.l.x
Again: check on GitHub under "Issues" which open Issues there are for a release, and/or google "Rails 3.y.z Problems" with the exact version number, so you get a feel of what problems could be introduced by upgrading to a new / the latest version.
I would recommend using Ruby 1.9.2 at this time.
Hope this helps