[qwertyboy]

Boy, do I have good news for you: http://conkeror.org/PDFViewer

Conkeror is so much Firefox, that you can easily fit the former with most things that work with the latter, including the built-in PDF extension. As a matter of fact, the Conkeror "binary" is just a shell script that launches Firefox or xul-runner with the proper config (something like: firefox -app /usr/share/conkeror/application.ini).

Also worth noting is that Conkeror was the original inspiration for vimperator (and thus for uzbl, dwb, luakit and the likes - all very splendid and worthwhile projects), and that this message is written on an editor spawned by conkeror (which, surprisingly enough, happens to be vim).