Personally, I think Acme::Comment lives in the wrong namespace: it should probably live in the Filter::Comment namespace or so.

I disagree with that. I think that namespaces like Filter::* and Tie::* should be restricted to module that deal with filtering or tieing. It's just not right to make the implementation part of the name space. Just think about it, should all modules that use objects belong in the OO::* name space? And what are you going to do with a module that uses a filter, is hence named Filter::Whatever, and then modifies its implementation so that it uses a different technique?

It's a bad, bad suggestion.

Abigail