Ruby 2.0.0 released on 24 feb 2013, marks the 20th anniversay of Ruby. rvm get stable This updates your rvm to the latest stable release. $ rvm install ruby It update system libraries and install ruby, so when i try $ rvm list rvm rubies =* ruby-1.9.3-p286 [ x86_64 ] ruby-2.0.0-p195 [ x86_64 ] # => - current # =* - current && default # * - default Now, install rails using gem install rails --version 4.0.0.beta1 --no-ri --no-rdoc