Author: Aaron Torpy.
Firefox is, by all accounts, a very good browser. Some would say and excellent browser. But the developers at Mozilla know it's not perfect, and that's why they've built an outstanding plugin system, which allows 3rd parties to improve upon Firefox by adding new functions and visual themes. Better still, they've made these extensions really easy to install (and uninstall, if required). The best bit? They're all small and thus quick to download (10's to 100's of kB).
The mozilla extensions page lists all of the extensions available for Firefox. There are thousands of these things; some are great, and some are just plain stupid. Below you will find the extensions that I've installed and not uninstalled again - i.e. the useful ones.
This extension allows you to preview all open tabs in one window, much like the Exposé feature in OSX (thus the name). An effective way to switch between tabs.
Link: addons.mozilla.org
If, like me, you cannot imagine functioning without your RSS feeds, you may have already switched to the Opera browser, which has a very nifty built-in RSS reader. Well, Sage levels the score for Firefox. Its interface is better than that of the other Firefox RSS reader extensions (eg. Wizz), and in some ways is better than that of the Opera reader. It's definitely worth trying.
Link: addons.mozilla.org
For more info on using Sage, please see my tutorial on the subject.
This extension allows you to add bookmarks directly into sub-menus of your bookmarks menu, using an 'add bookmark here' option (just like in Opera).
Link: addons.mozilla.org
This extension allows you to shuffle and/or hide items in the Firefox status bar (at the bottom of the window). If you've got a lot of extensions loaded, like I do, this is very useful.
Link: addons.mozilla.org
This extension puts the page-loading progress-bar into the background of the address bar, which looks kind of pretty (Opera does this). This extension may not work with all visual themes.
Link: addons.mozilla.org
Disable Java and JavaScript from websites for safer, faster, ad-free browsing.
Link: addons.mozilla.org
Note: NoScript will also disable useful scripts from trust-worthy sites, such as those in web-applications like e-mail clients, 'Web 2.0' pages (Slashdot, etc), and just about everything with an image gallery (even this site). The good news is that you can easily unblock these scripts on a per-domain basis, meaning you can allow scripts from sites you already know and trust, while automatically blocking those from new sites that you might not trust just yet.
IE Tab allows you to view a page in Firefox using the Internet Explorer rendering engine. This is most useful when dealing with old-and-broken IE-only sites, or when developing and testing good cross-browser pages. You can even set some pages to always load in IE tabs.
Link: addons.mozilla.org
A handy HTML validator, using the 'Tidy' validator that's built-in to Firefox (i.e. does not use external on-line validators like W3C's service).
Link: addons.mozilla.org
A nifty click-and-drag interface for measuring the size of page elements in your browser. Useful for web-developers.
Link: www.kevinfreitas.net