rbenv
sudo yum install -y autoconf automake bison bzip2 curl gcc gcc-c++ gdbm-devel git-core libffi-devel libtool libyaml-devel make ncurses-devel openssl-devel patch readline readline-devel sqlite-devel zlib zlib-devel
git clone https://github.com/rbenv/rbenv.git ~/.rbenv
git clone https://github.com/rbenv/ruby-build.git ~/.rbenv/plugins/ruby-build
add this to e.g. .profile
if [ -e $HOME/.rbenv ]; then
export PATH=$HOME/.rbenv/shims:${PATH}:${HOME}/.rbenv/bin
eval "$(rbenv init -)"
fi