The good CPAN times :-) It was a bit of a cumbersome thing to work with as a newbie back then but at least it handled dependencies very well.
And I'm saying this as someone that dislikes Perl a lot.
CPAN is the defacto Perl standard, mirroring and testing built in. With perlbrew, localLib and cpanm, the tooling for Perl is world class. I think Ruby and Python are still catching up here. No doubt they will, but CPAN is an amazing feat of engineering.