The purpose of Alien modules is to provide external libraries or other dependencies for CPAN packages. This Alien2 Manifesto updates the original Alien module description based on practical lessons from existing Alien module implementations and some perceived limitations.

The original Alien manifesto provided the idea but not a framework for how modules in the Alien namespace were to work. The plan was to "let evolution work for us and see what individual Alien packages need and then eventually factor it out". We are now more tha…