The About:config panel in Firefox allows you access to hundreds of different settings that otherwise might not have an interface to configure them. It’s one of Firefox’s stronger features, in my opinion. Unfortunately, the Preference Name isn’t always very descriptive. If you have Firefox 4 and use the About:config window, you should install the add-on, What’s That Preference?, for assistance with finding out what those preferences control.
The add-on simply adds a line to the context menu when in the about:config menu. It will open a tab to the MozillaZine Knowledge Base page for the preference that you right-clicked on.
Version 0.2 will add some requested features soon.
Upcoming: Version 0.2 (currently pending approval) will add two more about:config context menu items:
“MozillaZine Group Reference” — if the preference does not have a page(“MozillaZine Reference”), try this. It links to another Knowledge Base page showing preferences for the preference’s group name, but in much less detail. For example, there is no page for bidi.numeral, but this link will show preferences (including bidi.numeral) beginning with bidi.
“Web Search” — performs a Google search on the preference name
Requires Firefox 4+.
Extension’s page on Mozilla.org Add-ons.