another thought: the documentation can hide a flat namespace.
on the filesystem the flat namespace could be broken up too by introducing several subdirectories (instead of /modules/Parser.pmod/ it could be just /modules/parsers/) which are added to the search path for modules.
so you get a flat namespace that the user does not see. the only remaining place where the user will see that namespace is when hitting tab in hilfe, or any other tool that lists all the available modules.
greetings, martin.