$ sudo apt-get install build-essential libssl-dev libreadline-gplv2-dev zlib1g zlib1g-dev libxslt-dev libxml2-dev libsqlite3-dev curl
$ sudo apt-get install git git-core
Full instructions: https://github.com/sstephenson/ruby-build
$ git clone git://github.com/sstephenson/ruby-build.git
$ cd ruby-build
$ sudo ./install.sh
Full instructions: https://github.com/sstephenson/rbenv
$ cd
$ git clone git://github.com/sstephenson/rbenv.git .rbenv
$ echo 'export PATH="$HOME/.rbenv/bin:$PATH"' >> ~/.bashrc
$ echo 'eval "$(rbenv init -)"' >> ~/.bashrc
Restart terminal
$ rbenv install 1.9.2-p290
$ rbenv global 1.9.2-p290
$ touch ~/.gemrc; echo 'gem: --no-ri --no-rdoc' >> ~/.gemrc
$ gem install bundler
$ gem install rails