1.9.1 isn't supported: http://edgeguides.rubyonrails.org/3_0_release_notes.html#rails-3-requires-at-least-ruby-187 http://edgeguides.rubyonrails.org/3_0_release

1.9.1 isn't supported: http://edgeguides.rubyonrails.org/3_0_release_notes.html#rails-3-requires-at-least-ruby-187 http://edgeguides.rubyonrails.org/3_0_release_notes.html#rai... That said, I am using 1.9.1 in production (non-Rails project) and have had almost no issues so far, apart from a few libraries that had to be updated, but that was mostly minor issues (e.g. #methods returns strings in 1.8 and symbols in 1.9).