It’s quite simple. Run these commands in terminal and you are set. The first command is for installing Ruby on Rails while the last ones are for installing the MySQL gem in order to use MySQL. This assumes you have MySQL as Benson pointed out.
sudo apt-get install build-essential rails
sudo apt-get install rubygems ruby-dev libmysql-ruby libmysqlclient-dev sudo gem install mysqlcomments powered by Disqus