libruby2.1 2.1.5-4ubuntu1 (amd64 binary) in ubuntu xenial

 Ruby is the interpreted scripting language for quick and easy
 object-oriented programming. It has many features to process text
 files and to do system management tasks (as in perl). It is simple,
 straight-forward, and extensible.
 .
 This package includes the 'libruby-2.1' library, necessary to run Ruby 2.1.
 (API version 2.1.0)