apt: git gcc g++ automake flex bison ruby-dev rubygems llvm-dev zlib1g-dev libyaml-dev libssl-dev libgdbm-dev libreadline-dev libncurses5-dev
yum: git gcc gcc-c++ automake flex bison ruby-devel rubygems llvm-devel zlib-devel libyaml-devel openssl-devel gdbm-devel readline-devel ncurses-devel
brew: git openssl readline libyaml gdbm
pacman: git gcc automake flex bison ruby llvm zlib libyaml openssl gdbm readline ncurses

apt: git gcc g++ automake flex bison ruby1.9.1-dev rubygems llvm-dev zlib1g-dev libyaml-dev libssl-dev libgdbm-dev libreadline-dev libncurses5-dev
yum: git gcc gcc-c++ automake flex bison ruby-devel rubygems llvm-devel zlib-devel libyaml-devel openssl-devel gdbm-devel readline-devel ncurses-devel
brew: git openssl readline libyaml gdbm
pacman: git gcc automake flex bison ruby llvm zlib libyaml openssl gdbm readline ncurses

Install ruby1.9.1-dev in case we are on an older version of Ubuntu.
Install ruby1.9.1-dev in case we are on an older version of Ubuntu.
