about:config A sizeable list of configuration options for the browser.

about: shows the start-up page that is shown before the home page. This page gives the version and copyright notices.

about:cache Shows statistics regarding the disk cache and what files/pages are cached locally. Can access the memory and disk cache entries from here.

about:plugins Lists what plug-ins have been loaded.

about:blank Just as you would expect, nothing but a blank (but useful) page.

about:mozilla Shows a quote from the Book of Mozilla.

about:credits A sizeable list of contributors to the browser project.

about:buildconfig Describes how this Mozilla/Firefox executable was built.

http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul

See also XUL

> I wouldnt mind reverting to 'classic' behavior (perhaps where it autofills on > history, and perhaps bookmarks, but not on search results) - anyone know if > this is possible? > > I've had a nosey through about:config and there's a bunch of stuff under > browser.urlbar which I was looking through but nothing really seemed exactly > right. > Based on http://tinyurl.com/6rsuxt, if you set browser.urlbar.maxRichResults -> 0 it'll disable that behaviour entirely. Take it back to the 'classic' behaviour, as it were.

see also

http://www.howtogeek.com/howto/internet/firefox/troubleshooting-problems-with-firefox-3-crashing-or-hanging