On Debian, Ubuntu, or Mint: install Ruby with chruby and ruby-build

chruby_ruby-build.sh

# Install apt-get packages:
sudo apt-get install build-essential openssl libreadline6 libreadline6-dev curl git-core zlib1g zlib1g-dev libssl-dev libyaml-dev libsqlite3-dev sqlite3 libxml2-dev libxslt-dev autoconf libc6-dev ncurses-dev automake libtool bison subversion pkg-config

# Install chruby:
cd
wget https://github.com/downloads/postmodern/chruby/chruby-0.2.3.tar.gz
tar -xzvf chruby-0.2.3.tar.gz
cd chruby-0.2.3
sudo make install

# Install ruby-build:
cd
git clone https://github.com/sstephenson/ruby-build.git
cd ruby-build
sudo ./install.sh

# Install 1.9.3 with OpenSSL:
ruby-build 1.9.3-p327 ~/usr/local/1.9.3-p327 --with-openssl-dir=`which openssl`

# Add the following to .bashrc (or .zshrc whatev):
. /usr/local/share/chruby/chruby.sh # Load chruby
RUBIES=(
  ~/usr/local/1.9.3-p327
  # Path to other Rubies here...
)
chruby 1.9.3 # Select default Ruby

# Close and reopen terminal.

chruby
#=> * 1.9.3-p327