Plugins and extensions—they're what made Photoshop such a bonanza from the late 1980s onward, and they gave it the market push to triumph over competitors who preferred to keep their tools and development completely in-house. It was a great idea—make your own product more valuable by letting other people enhance it for their own benefit—and it worked famously. In the graphics world, everyone's got 'em now. But, in the browsing world...well, it takes an open-source project to apply that kind of functionality across categories.

Firefox did it, and it's one of the innovations that has helped Mozilla claw its way up from the bottom of the stack in the browser wars. Even though Internet Explorer still comes bundled with Windows, and Safari with Mac OS, and Konqueror with KDE, users across platforms opt for Firefox with greater and greater frequency. It's not just the tabbed browsing, or the built-in pop-up blockers, or the standards-compliance or the built-in search box—it's also the add-ons.

The Mozilla Project's plugin-based architecture turns a solid application into a customizer's paradise. The projects available on the Mozilla Add-ons site now stretch into the thousands, which gives the end user the opposite problem of the no-choice straitjacket of certain other browsers. The embarrassment of riches means too much choice, and figuring out how to narrow it down is no mean task.

The extensions come in a variety of flavors—from add-on applications to interface tweaks to toolbars. Here are a few that most users will find very handy. They extend functionality, enhance privacy and give users a leg up on taking their favorite content with them wherever they wish to go.

Web pages are great things. The democratization of media that the Internet brings us means that everyone has a Web site, and it's a great thing. There's only one problem with everyone having a Web site: everyone has a Web site—even people who think it's cute to have their own personal radio station running any time you log on to one of their pages.

I may be a curmudgeon, but as much as I care about the teeming masses of humanity on-line, that affection does not extend to being willing to tolerate someone else's attempt to soundtrack my corner of the universe. It's been the case for several years now that if you wanted to surf around on MySpace or thumb through your Aunt Estelle's family photo albums on her personal site, you had two choices: endure the autoplay music, or turn your speakers off.

Not anymore—not if you surf with Firefox. Sun Chun-Yen's Stop Autoplay extension automagically toggles off all autoplaying media, and it allows you to blacklist Flash media providers if they get on your nerves. With Stop Autoplay installed, instead of embedded media assaulting you before the page finishes rendering, you are presented with a little red box with a Play button inside it. If you are inclined to listen to the embedded media, you have the option at your fingertips. If you're not, it won't bother you. It's a beautiful little plugin. It's simple, elegant and “just works”. It also can help save you from vicious attacks by coworkers who don't like the autoplayed music either.

Protecting you from your boss (who actually expects you to be working when you're on the clock) is the noble quest undertaken by another add-on, Panic. Panic sets up a hotkey that, when pressed, will close all open tabs and open a tab containing the URL of a page you're actually supposed to be looking at. Note that it closes the tabs, it doesn't hide them. Once you press your user-definable hotkey, they're gone. Sure, trudging through the browser history to re-find that amazing article on “Linux Home Automation: the Ultimate Internet-Controlled Gun Cabinet” can be a drag, but when it saves you an unpleasant conversation with your boss, it's worth the price.

On a related note, there is an extension that protects you from inconvenient questions from young children, nosy roommates and casual snoopers at neighborhood coffee shops. If you've ever heard the words “Mommy, what does 'stud' mean?” or “Daddy, what's burka porn?” from a five-year-old who has apparently appeared at your elbow from a neighboring dimension, you know what I mean. The Net sucks you in, and sometimes someone walks up behind you and starts reading over your shoulder—or worse, reading the names of the other tabs you're saving for later—and you don't notice them for a few hours...um, minutes.

Enter TabRenamizer, an extension that lets you protect your privacy by renaming the tabs in your open browser windows. It integrates seamlessly with Firefox, sitting as a menu option in the Tools window that lets you set it either to rename all future tabs or to rename all open tabs randomly. You also can rename an individual tab selectively by right-clicking on the tab title and selecting the now-present rename this tab option from the context menu. This gives you a renaming dialog so that you can give the tab any name you want.

If there's anything out there that could push me to buy a video-capable portable media player, it's the Authors@Google series on YouTube (and similar lecture series available on Google Video from various think tanks and science conferences). Science, public policy, arts discussion—the Net has everything a growing brain needs. Unfortunately, a lot of it isn't in easily downloadable podcast form, but it's sequestered in various video formats behind the YouTube Flash curtain or hiding in other embedded players. Bringing it down to the hard drive, even just in audio form, used to be a pain and a half, often requiring some fancy stream ripping involving speaker wires and mencoder scripts. Not any longer. Now, there are a bunch of extensions and Greasemonkey scripts for Firefox that let you rip your beloved content from the cold, uncaring fingers of the Internet and then load it on your portable media player to take with you to family reunions. Two of them are worth special note.

The first is Fast Video Download, which, as its name suggests, will let you download pretty much any embedded video with the click of a mouse. When you call up a video on YouTube or Google Video or just about anywhere else, and it's one you want to take with you for viewing on the commuter train or for listening to at the gym, simply click on the handy-dandy video downloader icon that appears at the bottom right-hand corner of the Firefox screen, and away you go. It pulls the video from the Web server, in whatever format it's natively stored, and drops it on your hard drive, from where you can load it onto your portable media player at your leisure. Fast Video Download's philosophy is no-nonsense and unobtrusive, and it either works on a given site or it doesn't—your mileage may vary.

The second is an extension called Download Helper, and it has a different approach. It maintains a compatibility list and a directory of video sites from which it can download and file types it keeps an eye out for. Accessing its submenu through the Tools menu on Firefox allows you to customize it, to allow or block adult and/or pornographic content, and it also has special entries to help you find instructional and tutorial videos. It's a more comprehensive tool than Fast Video Download, but it's also less elegantly integrated into Firefox. Although Fast Video Download is the tool you want on hand when you stumble across something you're going to want to listen to again later, Download Helper is a tool better suited for dedicated video hunts (say, if you're doing research or you're going to be on a long plane ride and want your portable media player loaded up with things you haven't seen before).

Not all Firefox extensions are little plugins or interface tweaks. Some of them are full-on, serious applications that just happen to run in a Firefox tab. There are quite a few of these, including a number of very good security auditing tools. However, today I'm focusing on must-haves for everyday users, so in this section, we're going to look at three tools that make the life of a normal Web 2.0 Netizen less hassle-prone.

If you're hip deep in new media, you've probably got a blog. And a Flickr account. And a YouTube channel. And a Box.net file repository. And a Facebook account. And a...well, you get the idea. There are a lot of passwords to remember, and a lot of files to upload, and a lot of really crappy, limiting interfaces through which you have to do that uploading.

File Uploader changes all that. It's essentially a specialized FTP client that's compatible with a number of on-line file services and social-networking sites. After installing the extension and restarting Firefox, you are presented on the Tools menu with a File Uploader entry. Click on it, and a new tab loads with the application. Using the accounts management and services menus, you can sign up for new accounts with any of the supported services (including, but not limited to, the aforementioned YouTube, Box.net, Flickr and Facebook), or use accounts you already have and manage your files and photo albums remotely. Reordering, batch uploading, deleting and renaming are all supported, and, unlike the HTML interfaces offered by the services, you are not subject to the files-per-upload limits that the Web interfaces impose. If you are, like me, a working photographer (or merely an avid hobbiest), and you're dependent on Flickr to showcase your work, this tool will save you a lot of time. If, on the other hand, you're a social-networking junkie, File Uploader will let you share more/better/faster with more people.

Although File Uploader is patterned after a classic dual-paned FTP client, it is not actually an FTP client. Instead, it emulates an FTP client over HTTP for particular services. For a true-blue FTP client that runs in a Firefox tab, you'll need FireFTP.

FireFTP is one of the oldest and most mature Firefox extensions around. It supports all the essential features you need in an FTP client—proxy support, multiple account support, integrity checks, encryption, hash and time synchronization. It operates on a classic three-pane view: local filesystem on the left, remote filesystem on the right and console data scrolling in a wide pane across the bottom. It also will keep local and remote directories synchronized, and it can do deep-tree comparison, so you can see what might be present on one filesystem that's absent from another. It's fast, it's light, and it works very, very well. Some standalone clients, like GFTP, have a few more bells and whistles, but they're the kind of features you use so rarely that you'll seldom need to call it up if you've got FireFTP handy. FireFTP is also cross-platform, unlike some of the other best open-source FTP clients, which are Linux or *nix only.

The other entry in the oldie-but-goodie pile is ChatZilla, a venerable in-tab IRC client with all the trimmings. Although it doesn't have the $@%!ing provocative veneer that bitchX does, it handsomely organizes chat channels, logs, has an extensive built-in list of available channels, supports DCC chats and file transfers, and has its own plugin and theming architecture. After install, just like FireFTP and File Uploader, you'll find it easily launched with a click from the Tools menu. In a sense, it's nothing really new—IRC is old tech—but it does implement all the standards very well, and for those who prefer to keep desktop clutter to a minimum but still enjoy fighting with random strangers on IRC, ChatZilla is a must-have.

The last of our full-on apps that just happen to run in a tab is NewsFox, an RSS newsreader for Firefox. It's a three-pane Atom/RSS feed reader laid out very similarly to an e-mail reader: feeds on the left, news items on the top right and story content on the bottom right. It handily auto-imports any Live Bookmarks you've got set up as soon as you launch it, so you don't have to worry about re-adding feeds to which you've already subscribed. Again, like FireFTP and ChatZilla, it's a solid, no-frills app that “just works” and does what it's supposed to do. And, also like ChatZilla and FireFTP, it doesn't cause a performance drag, which is a welcome change from the bad-old days when Firefox was new and full of memory leaks all the time.

As you can see from the above, Firefox extensions give people a lot of power over their browsing experience—indeed, a lot more than most anyone is used to having. But aside from the obvious minor advantages of time saved, extra utility and fun, it also can be a major force for good in the world. This is certainly the case with Free Access Plus, a filter-buster put out by an innovative developer going by the name of MohammedR. It's a notion that I can only hope someone in Hong Kong picks up on. Imagine Radio Free Europe in your browser and you get the idea. Free Access Plus circumvents state censorship of the Internet—particularly, it circumvents the Iranian government's content filters that block YouTube, del.icio.us, Flickr, Technocrati, FriendSter, LiveJournal, MySpace and a number of others. It also purports to circumvent similar filters imposed by other governments. It's not a perfect solution, and it doesn't work all the time, but it is successful some of the time, and it's exactly the kind of thing open source is best at—opening the world to all people, even when their governments think they know better.