Kwalitee is a concept created and promoted by CPANTS. Some background on it:

• cpants.cpanauthors.org/kwalitee — Kwalitee indicators
• qa.perl.org/phalanx/kwalitee.html — What is Kwalitee? (this seems like a useless page)
• blog posts
  • two blog posts on perl.com
  • marmanold.com/tech/perfect-perl-kwalitee/ — "Perfect Perl Kwalitee"
  • "Improve your (Perl) code Kwalitee"

Modules related to Kwalitee:

• Module::CPANTS::Analyse and other modules in that distribution — Generate Kwalitee ratings for a distribution
• Test::Kwalitee — Test the Kwalitee of a distribution before you release it
• cpants_lint and App::CPANTS::Lint — front-end to Module::CPANTS::Analyse