Today, Rails core member Jeremy Kemper dropped the words that lots of ardent Rails developers have been waiting for: “Rails 3 beta is LIVE.” It’s true! Rails 3.0’s first approved beta/pre-release version is now live and ready for you to install.
Unfortunately, the installation process isn’t as easy as Jeremy explains. RubyGems doesn’t support the installation of prerequisites on pre-release gems, so you need to install them all manually. I think I have some instructions to cover that (works on 1.8.7 and 1.9.1):
gem install i18n tzinfo builder memcache-client rack rack-test rack-mount erubis mail text-format thor bundler # remember to prefix with "sudo" if your environment needs that
And then, finally:
gem install rails --pre
Worth reading next is a retrospective and summary of the work done for Rails 3.0 so far by Yehuda Katz.