I'll probably start with SchmonzDoc. I implemented the basics over two years ago. If it had half the features that have been flying around in my head ever since, it'd be mind-bendingly useful.
Any recommendations for a development environment that makes Perl programming more productive? I've seen (mostly payware) Perl IDEs for Windows and Linux; I'd prefer something free, with source code available, that can also run on any old Unix and/or Mac OS X. I'm awfully picky, I realize this, but I've been spoiled rotten by Mozilla and Eclipse.