smarty3 3.1.21-1 (amd64 binary) in ubuntu xenial

 Smarty is a template engine for PHP. More specifically, it
 facilitates a manageable way to separate application logic and content
 from its presentation.
 .
 Smarty 3.1 is a departure from 2.0 compatibility. Most notably, all
 backward compatibility has been moved to a separate class file named
 SmartyBC.class.php. If you require compatibility with 2.0, you will
 need to use this class.