Weirdest module I've ever written: Pod::HTML2Pod. Yes, it turns HTML into Pod. Write your documentation in HTML, and turn it into Pod. The source code is horrendous, tho.
Module whose design I put the most thought into: Pod::PXML. It turns Pod into an XML instance, and back. The hard part was the specifics of the instance's doctype. What a "=item" looks like, etc.
Hard because there's so many ways to do it; some better for some things,
some better for others. Compare its doctype
to the much more verbose doctype from Matt Sergeant's
Pod::XML. Now that
I've written perlpodspec and gotten pod more sorted in my mind, I'm beginning
to think Pod::PXML should be a tiny bit more like Pod::XML's doctype.
Notably, now that I have stipulated all the kinds of "=over...=back" regions there
are, and decided that the first paragraph after the =over should dictate the
type, I sort of wish that an "=over / =item *