tool to compile and install different versions of Ruby

 ruby-build provides a simple way to compile and install different
 versions of Ruby.
 .
 ruby-build is great when you want to build Ruby versions that are not
 available via APT, for example if you need legacy or bleeding edge
 versions of Ruby.
 .
 Combined with rbenv, ruby-build lets you easily install and switch
 between different implementations of Ruby, such as MRI, JRuby, REE
 and others.