Moose minus the antlers
Moose, a powerful metaobject-fueled extension of the Perl 5 object system, is wonderful. (For more information on Moose, please see 'perldoc Moose' after installing the perl-Moose package.) Unfortunately, it's a little slow. Though significant progress has been made over the years, the compile time penalty is a non-starter for some applications. Mouse aims to alleviate this by providing a subset of Moose's functionality, faster.