in reply to OO-Perl Question: How Do I get a List of derived Classes for a Base Class?

Have a look at Class::MOP and more specifically Inheritance_Relationships from Class::MOP::Class.

It has two methods that could be useful for you:

$metaclass->subclasses
This returns a list of all subclasses for this class, even indirect subclasses.
$metaclass->direct_subclasses
This returns a list of immediate subclasses for this class, which does not include indirect subclasses.

CountZero

A program should be light and agile, its subroutines connected like a string of pearls. The spirit and intent of the program should be retained throughout. There should be neither too little or too much, neither needless loops nor useless variables, neither lack of structure nor overwhelming rigidity." - The Tao of Programming, 4.1 - Geoffrey James

In Section Seekers of Perl Wisdom