This is where, for all its mistakes, perl5 has won big - the core language itself provides basically an OO construction kit, and so over the years CPAN has iter

This is where, for all its mistakes, perl5 has won big - the core language itself provides basically an OO construction kit, and so over the years CPAN has iterated repeatedly towards better object systems. The latest, Moose, which is rapidly taking over the perl world, comes close to providing a superset of the features available in competing languages - and with the advent of the Devel::Declare syntax creation system we're able to add new keywords to support this, resulting in the MooseX::Declare system. While people often complain that perl5 should have these things out of the box, I think it contributes to the longevity of the language to be able to provide them externally on a solid core - if somebody comes up with a better set of ideas, new code can switch to using those, and current code will be unaffected - as we're currently seeing with projects using Moose for new code without having to touch any of their existing classes.