Well I've already gotten ipdf to plumbed to accept multiple formats and all I need do now is write and plug in adapters.
If you want to get your er_registry.txt files ready, the new XPDF entry looks like this:
Code:
[XPDF]
category=viewer
arguments=<FILENAME>
exec=/usr/bin/xpdf
xResourceName=win
channel=2
extensions=pdf;PDF;djvu;DJVU;rtf;RTF;zip;ZIP
The zip entries let you feed in Baen eBooks with out needing to unzip them, or you can just rename them to rtf. The plumbing is clever enough to route content based on examination of what its fed, regardless of the file name extension. (already tested this part)