PeterFirefox is a great browser, and part of that is it's extensibility. As well as extensions and themes, Firefox also has an extensive set of hidden preferences that you can't get to through the graphical Preferences dialogue.
Instead, you can access them via the built-in about:config URL (just visit that in Firefox).
#1 - setting cookies for 'sites you navigate to' only
In a strange move backwards, this feature disappeared from the graphical Preferences dialogue as of Firefox 2.0. What it does is that it only sets cookies for sites you actually visit (i.e., not intrusive advertising programmes).
From about:config, search for cookie and find network.cookie.cookieBehavior Double-click it and change the value to 1.
#2 - set backspace to go back a page (Linux only)
As of Firefox 2.0, pressing backspace no longer heads back a page under Linux. Fix this by searching for browser.backspace_action and change it to 0.
#3 - always display menu bar in popups
Legitimate popups are great, but sometimes it's nice to have access to the Firefox menu bar in the popup.
Again, in about:config, find dom.disable_window_open_feature.menubar and double-click it to toggle it on.
#4 - always display toolbar in popups
Just like the last one, but this will show the toolbar instead of the menu bar in all popups.
You'll need to double-click on dom.disable_window_open_feature.toolbar to toggle it on.
#5 - disable installation of extensions and themes
If you're setting up Firefox in a configuration where you don't want people messing around installing extensions and themes, you can easily disable them.
Note - it's easy to get round, as anyone else who knows this tip can browse to about:config and can reverse the setting, so it will only deter casual meddlers.
Search for xpinstall.enabled and double-click it to toggle it off.
Parting words
This was just a very quick round-up of little Firefox tricks you might not have known about. I'm sure there are many more good ones, so if you know a killer about:config hack, let us know in the comments!
UPDATE: aussiebear posted a great #6 in the comments, so I've reposted it below!
Here’s number 6: Reduce memory consumption.
(Tested on both Windows AND Linux versions).In Firefox, enter in the web address line:
=> about:configThen enter in the “Filter” line:
=> browser.cache.disk.capacityBased on how much system memory you have enter the following to modify the value:
For 128MB to 512MB RAM => 5000
For 512MB to 1GB+ RAM => 15000
(These are typical values that work for most people. You may use other values if you wish, depending on your web surfing habits).Then restart Firefox.
For some stupid reason, they set it to something like 200000 by default!
You wonder why Firefox consumes 100+ MB of RAM!
I can also confirm that this works with the Mac OS X version of Firefox too, so if Firefox is being a memory hog, give this a try. Thanks aussiebear!
