It's no secret I'm a fan of Mozilla Firefox, and one of it's most useful features, in my opinion, is the ability to add functionality through the use of extensions. In the past several years, I've found quite a few extensions that either are extraordinarily useful under certain circumstances, or else so much a part of my browsing experience that I can't imagine surfing the Web without them. So for your edification (and my own convenience, since I'm finding myself installing Firefox fairly often recently), here is my list of the 10 most useful Firefox extensions.
10. Stop-or-Reload Button — This simple extension simply combines the Stop and Reload buttons so that only the relevant button is visible. Not only does it save space, it's great for compulsive clickers, such as young children, who might prevent a page from loading by repeatedly clicking the Reload button in the hope of making it load faster.
9. ProCon Latte — ProCon Latte is a must-have extension for any parent! ProCon Latte is a content filter for Firefox, which prevents unwanted Web pages from loading based on both the site's URL and the site's content. It can also block all Web sites except those explicitly added to a whitelist. The extension is password-protected to prevent determined children from simply changing the settings. ProCon Latte isn't perfect — currently, it can still be disabled from the Add-ons menu, and on the highest settings it may block acceptable Web sites — but it's still incredibly useful. Of course, this extension doesn't prevent kids from browsing to naughty sites using IE, but parents can put a stop to that by disabling IE in Windows by going to Set Program Access and Defaults and unchecking "Enable access to this program" next to IE. Of course, your kids should be using a limited account which would prevent them from changing this setting, as well as other undesirable things such as indiscriminately downloading and installing malware- and virus-laden programs. The issue of using the Add-ons menu in Firefox can be avoided by using another handy extension, Menu Editor, to simply remove that option from the Tools menu.) While ProCon Latte is no substitute for more comprehensive parental control software, it's a good start.
By the way, if ProCon Latte doesn't provide enough control over your kids' Web browsing, you may want to look into another extension, Glubble Family Edition. Glubble uses a Web service to allow parents to control exactly which sites the kids are allowed to view. I prefer ProCon Latte both because it doesn't require a (albeit free) registration to a Web service, and because Glubble dramatically changes the way you browse the Web.
7. QuickProxy — If you have a laptop that you carry between home and either school or work, and one or the other is behind a proxy, you know how tedious it is to constantly be changing Firefox's proxy settings. QuickProxy allows you to switch between different proxy settings with a single click. While other extensions, particularly FoxyProxy, provide many more features, the sheer simplicity of QuickProxy makes it much more attractive in my opinion.
6. Image Zoom — One of the few downsides of newer high-resolution monitors is that they make everything look small. While Firefox makes it relatively simple to increase the text size of Web pages, it doesn't provide any means of doing the same for images. That's where Image Zoom comes in handy. With a simple click on the context menu or a roll of your scroll wheel, you can easily increase or decrease the size of any image on a page.
5. IE Tab — Unfortunately, there are still a few clueless Web developers out there who assume that everyon uses IE, and design their sites accordingly. While rare, it is a continual annoyance to us Firefox users to have to open up IE just to view these sites. IE Tab alleviates this annoyance by allowing you to open a Web page with IE, but within a Firefox tab. With IE Tab, it's even possible to open and use Windows Update using firefox!
4. FoxyTunes — If you're like me, you like to listen to music while surfing the Web, which means you probably have to switch back and forth between Firefox and your media player. With FoxyTunes, you can control your media player from within Firefox! The simple controls are compatible with numerous media players including WinAmp, iTunes, Pandora, Windows Media Player, Musicmatch, XMPlay, MediaMonkey, Media Player Classic, Real Player, XMMS, Noatun, Amarok, Rhythmbox and many others.
3. Tab Mix Plus — This extension provides much-needed enhancements for two of Firefox's best features: tabs and sessions. With Tab Mix Plus, you can control almost every conceivable aspect of your tabs, from the size of the tabs, to the options available in tab context menus, to whether or not your Bookmarks open in a new tab. You also get a session manager that is considerably better than Firefox's built-in session manager, which offers more options and even the ability to recover from a crash! I consider this a necessity for everyone, if only for the session manager.
2. DownThemAll! — One of the weaker features of Firefox is its rather simple download manager, which is lacking many features you'd expect of a modern download manager, including the ability to queue downloads. DownThemAll! is a full-featured download manager fully incorporated into Firefox. With DownThemAll!, you can not only queue your downloads, pause and resume downloads, and continue partial downloads, but you can also download all links or images on a page with a single click. DownThemAll! also increases download speeds by better utilizes your bandwidth with multi-part downloads. For those who prefer to use stand-alone download managers, you may want to look into FlashGot instead.
1. Adblock Plus — The uncontested #1 best Firefox extension, Adblock Plus is such an integral part of my browsing experience that using a Web browser without this extension is truly jarring. Adblock Plus does exactly what you'd expect from the name — it blocks ads. Adblock Plus uses a blacklist to block advertisements from known ad services and providers, and you can easily add to this list either manually or with a simple click on an offending item. This extension is great for anyone — it's truly amazing how much more pleasant browsing can be without being constantly assaulted from all sides by intrusive advertisements — but it's particularly useful for parents (since many ads may contain adult content) or for individuals with slower Internet connections, since Adblock Plus doesn't simply prevent items from being displayed, but prevents them from being downloaded at all, noticeably improving page load times. I really can't say enough good things about this extension, so try it for yourself!
Honorable Mentions — In addition to the additional extensions I mentioned while discussing my top 10, here are a few more that didn't quite make the list for one reason or another, but are nonetheless worth a look.
FasterFox — FasterFox allows you to tweak certain of Firefox's network settings to speed up browsing. It also has an optional pre-fetching feature that silently loads and caches all of the links on the page you are browsing, so that if you browse to one of those links, the page will be displayed much faster. This didn't make my list for two reasons. First, while I haven't personally experience this, some people have reported that FasterFox inexplicably made Firefox slower rather than faster. Second, some sites don't like pre-fetching, and will give you an error message if you browse to such a site. While such sites are few and far between, and disabling FasterFox's pre-fetching feature isn't difficult, it's still a bit of an annoyance.
Tab Preview — Tab Preview displays a thumbnail of a tab when you mouse over the tab on the tab bar. You have quite a few options available such as setting the size of the preview thumbnail, and overall it's a pretty nifty extension. It didn't quite make my top 10 list because I simply don't think it's that useful. Sure, the preview thumbnails are nice, but takes almost as long for the preview to display as it would to switch to the tab, somewhat defeating the purpose of the preview. If the preview displayed a bit faster, it would probably make my top 10.
ChromaTabs or ColorfulTabs — Some people may question why Stop-and-Reload Button made my list, but either of these arguably more useful extensions didn't, and it's a reasonable question. ColorfulTabs colorizes tabs in the tab bar to make it easier to distinguish separate tabs, while ChromaTabs takes this on step further and sets specific colors for different Web sites. Both extensions make it simple to distinguish between multiple tabs at a glance. The problem is that both of these extensions have known compatibility problems with some themes, as well as some extensions that modify tabs, such as Tab Mix Plus. I can't in good conscience recommend extensions that may conflict with each other. Stop-or-Reload Button conversely doesn't have any such compatibility problems, and is so simple and elegant that it seems like it should be an option integrated into Firefox. However, if you aren't using Tab Mix Plus (which I do highly suggest) or any other extensions that modify tabs, you may want to look into one of these.
Nuke Anything Enhanced — This is another extension that almost made the list, and only didn't because it's only useful in certain situations (though in those situations it's incredibly useful). Nuke Anything Enhanced adds the option "Remove this object" to the context menu which causes an element of the page to not be displayed. Unlike Adblock Plus, this is only temporary, and the object will again be displayed, which means this extension is most useful in removing unwanted objects from a page before printing. If removing objects were more permanent, this would definitely have knocked Stop-or-Reload Button out of the #10 spot.
Firefox Environment Backup Extension (FEBE) — This extension is potentially quite useful. It makes regular backups of your bookmarks, preferences, extensions, themes, passwords, and cookies, so they can be easily restored or transferred to another machine. Unfortunately I've had a few problems with this extension. It does fine backing up extensions and themes, but while it seems to back up other information such as passwords and preferences, I have yet to get it to successfully restore that information. Considering that the point of this extension is data backup and recovery, the unreliability in restoring backup information is, in my opinion, a fatal flaw. If the bugs are ever worked out, this would easily move up to the middle of my list.
Noia 2.0 (eXtreme) &mdash This only reason that this didn't make my list is that it's not an extension! This is probably the most pleasant and attractive theme for Firefox I've seen. Others may have a nice layout, or an attractive icon set, or a good color scheme, but this one has it all. Unlike a few other themes, I haven't encountered any compatibility problems with any extensions. Noia is, without a doubt, my personal favorite theme available for Firefox.