Becareful with categorizing the entire world. While OOP forces a tree relationship, if you don't multi-inherit, it's not that simple outside of OOP. Using your examples, I can provide easy counter examples:

For some reason, someone I know wrote an XML processor that generates and executes tests. I personally know XSLT, which is XML, can be used as a template system.

I think the CPAN categories are mostly intelligent, with holes. Why switch to another intelligent system with other holes? :)

Update: Congratulations on being the reason I posted post 500. ^^