Moose is an extension of the Perl 5 object system.
Moose is built on top of Class::MOP, which is a meta-class system for
Perl 5. This means that Moose not only makes building normal Perl 5
objects better, but it also provides the power of meta-class programming.
Moose is different from other Perl 5 object systems because it is not a
new system, but instead an extension of the existing one.
While Moose is very much inspired by Perl 6, it is not itself Perl 6.
Instead, it is an OO system for Perl 5. I built Moose because I was
tired or writing the same old boring Perl 5 OO code, and drooling over
Perl 6 OO. So instead of switching to Ruby, I wrote Moose :)