Module::Pluggable provides a simple but, hopefully, extensible way of having
'plugins' for your module. Obviously this isn't going to be the be all and end
all of solutions but it works for me.

Essentially all it does is export a method into your namespace that looks
through a search path for .pm files and turn those into class names.

Optionally it instantiates those classes for you.

WWW: https://metacpan.org/release/Module-Pluggable