This list is culled from a straight listing of the most popular posts that offered a Firefox extension for download in 2009. We're not including posts about configuring Firefox, or even our own hand-rolled Firefox add-on packs—even if they were pretty popular, too. Let's get to the good stuff.

Firefox 3.7 Theme Makes Your Browser Look Awesome

One of the greatest things about Firefox is that its development happens way out wide in the open. When the design workers start coming up with preliminary sketches of a new release, anyone can peek at them and even compile them into a theme, which does just what the headline suggests.

All-Glass Firefox Enables Slick Transparency Effects

Windows Vista and 7 feature some fairly nice looking transparency effects, but if your primary browser doesn't use them, it can feel a bit disconnected. All-Glass Firefox v2 tweaks your browser to look just, well, proper in its fancy-pants surroundings.

"Vacuum Places Improved" Speeds Up Firefox with a Click of Your Mouse

You can speed up Firefox by cleaning up its fragmented database, and the Vacuum Places Improved 0.3 extension automates that admittedly pain-in-the-butt process.

Gmail Redesigned 3.0 Focuses on Speed and Message Space

Google Redesigned, a multi-site suite that trades Google's blue/white/minimal look for a darker, sleeker feel, kept improving its transformative powers this year, adding a host of improvements in its 3.0 release, and later releasing a new version with GReader Redesigned for the RSS hounds.

Dislike 0.2 Adds a Disapproving Dislike Button to Facebook

"I'm having SUCH a bad day—the cleaning lady TOTALLY left her Pine Sol smell all over my bed linens!" That, my friends, is why clever JavaScript tweakers created the Dislike extension.

TinEye Adds Reverse Image Lookup to Firefox

Many of the pictures and illustrations you find across the web aren't in their original form—and many can be had at better, perhaps more wallpaper-worthy sizes. The TinEye extension makes it a simple right-click maneuver to search out similar copies of any image you come across.

SkipScreen Lets You Pass Go and Collect Your Download

Sometimes, great stuff has to be hosted on public download services, because the file—or the attention it's getting—is just too much for our meek little personal sites. And the download sites often make it as painful as possible to grab those files. SkipScreen acts as an automated intermediary, jumping through the necessary hoops and entering the key presses required.

FireFound Tracks Your Stolen Computer, Nukes Your Personal Data

This neat little extension, winner of the Extend Firefox 3.5 contest, utilizes lots of Firefox's built-in features, like geo-location and the extension framework, to offer wary laptop users a way to nuke their personal data, passwords, and history if necessary, track where their machine is logging on after a theft, and cull all kinds of data from the thief. FireFound is, in other words, a smart thing to install if your laptop ever leaves the home.

Gui:config Gives Easy Access to Hidden Firefox Settings

A lot of helpful stuff is tucked away in Firefox's about:config menus. Gui:config brings them into focus and offers a graphical way to manage them. As the How-To Geek puts it, it's amazing that this isn't something being considered for mainstream distribution in the browser.

Memory Fox Manages Firefox's Memory Use, Aims to Keep It Low

(Windows only): Firefox is decently light with memory on startup, but extensions and plug-ins drag it down as you actually use it. Memory Fox monitors Firefox's memory use and, once it reaches your pre-set limit, whips it back into shape.

Daum Blue Firefox Theme is Clean, Simple, and Elegant

(Windows only): Well, the headline and picture kind of say it all about Daum Blue, but it's worth noting that beyond looks, it's also fairly customizable, and looks even better on Vista and Windows 7 systems.

Decreased Productivity Helps You Browse at Work Without Getting Busted

Sure, kind of anathema for this site's stated mission, but giving your mind a break at work has real mental benefits, even if your boss doesn't think so.

UrlbarExt Adds Super Powers to the Awesome Bar

If you're likely to do more at a web site than just simply bookmark it, UrlbarExt is like a Leatherman for your AwesomeBar. Head to a site's root, search the site on Google, and do much more from a small array of address bar buttons.

Foxmarks Becomes Xmarks, Adds Search and Suggestion Features

Another headline that pretty much says it all. We weren't a big fan of Xmarks' new "discovery" features, but its growing reach into Chrome and other browsers make the former Foxmarks' expansion a good thing.

Magnetiser Downloads Torrents When No Torrent File Is Available

Given the recent legal crackdown on BitTorrent-centered sites, magnet links (explained here) are increasingly popular. Magnetiser makes it easy to track down a working torrent link to grab the file you're looking for.

Integrated Gmail Updates with Improved Looks and Handy Features

It must be mentioned that, beyond smooshing together Gmail, Google Calendar, and Google Reader into one neatly-arranged Gmail page, Integrated Gmail also customizes every niggling detail of those combined apps, making it worth the try-out, even if you think you like your Google spaces separated into different tabs.

Omnibar Extension Collapses Firefox's Address and Search Boxes into One

Omnibar is one of the clever ways Firefox can make itself into a Google Chrome clone, and we love that kind of openness 'round here.

Invisible Hand Subtly Shows Best Web Prices

If you're always looking at online purchases and wondering if you could save more before pulling the trigger, Invisible Hand affirms your hunches for you, dropping down and showing lower prices wherever it can find them.

Ubiquity Sees Major Update, New Look, Better Performance

Mozilla's future-facing automation and shortcut engine, Ubiquity, continued to get awesome-r in 2009.

App Tabs Creates Permanent, Icon-Only Tabs, Firefox 4.0-Style

We dug the idea of permanent, favicon-only tabs when a helpful reader explained it to us, but the App Tabs extension took a multi-step process and made it far more simple.

Based on Opera's reports of their new JavaScript engine, Caraken, being "7x faster" than the standard Futhark engine built into Opera 10.10, we ran it through Mozilla's Dromaeo JavaScript tests, which combine Apple's SunSpider and Google's V8 JavaScript benchmarks. Pure runs-per-second speed isn't everything, of course, and engines can be built specifically to max out in these kinds of tests. That said, the results of Opera 10.5, rolled into our last round of browser speed tests, were more than a little impressive, using Dromaeo as a measuring stick:

The chart up top is pulled from our most recent speed tests, with Opera 10.5 pre-alpha results rolled in. It shows some, shall we say, notable improvement. The gHacks blog put 10.5 against Firefox 3.6 beta and Chrome's development build in the SunSpider and V8 tests and found that Opera either beat, or came very close to, Chrome, in those separate runs, and usually left Firefox in the dust. We'll have to put Opera 10.5 through its full paces when it's out of its very unstable build.

If you're the adventurous type and do want to give the pre-alpha a try, you'll also find improvements to the page rendering engine, new Private Browsing tabs and windows that don't track any history, and some interface and visual design tweaks, detailed in the post below. The big JavaScript improvements aren't as pronounced on the Mac build as on Windows, according to the development team, but are still there.

Opera 10.5 pre-alpha is a free download for Windows and Mac systems. Tell us if you think there's some real speed-ups in this build, and what else you like, in the comments.

This is good (or maybe just intriguing) news for Firefoxtards like myself who cant bear to part with their precious extensions, but like some of Chrome's features. And since this isn't really official news, details are rather thin. [Nick.Pro via Google Operating System via Lifehacker]

Back when Microsoft snuck up behind Netscape and stole its crown, hardly anyone knew that there was even a playing field, let alone a game. Following all that anti-trust business, Microsoft's only major competitor was the product of a non-profit organization. Firefox is popular, it's what I'm using now, but it doesn't have what it takes to be a superpower in a browser war.

What does it take? Cash money. Many of you know that Google is the reason Firefox did so well in the first place: As far back as 2005, Google was paying major dollars to those who referred Firefox downloads that included the Google Toolbar. But Firefox never seems to have had the cash to buy its way to the PC makers' desktops. The kind of payola that puts heinous crapware on Dells, HPs and other PCs will soon be put to work in the new browser war, one where Microsoft will for the first time have a serious threat on its home turf.

As Electronista puts it, though Microsoft was long ago forced to allow other default browsers...

...these have typically been limited to Firefox and the now-defunct Netscape but will now potentially have a more commercially supported alternative that also emphasizes universal web standards, the historical weaknesses of Microsoft's browser.

TechCrunch adds:

The Google’s open source browser has a number of eager customers, including OEMs who can’t offer the browser until it is in full release.

Rules is rules, so you can see why, at least in this one Google product, the beta label is a major hindrance. To recap:

Browser gold status + web standards + sick payola = hot Chrome takeover strategy

All the plan lacks is a Mac-friendly version to impress all those ivory-tower newsmedia people (and MacBook totin' bloggers), and that's due sometime very soon. Stay tuned for one fierce freakin' browser war, is all I'm saying. [TechCrunch via Electronista]

Last time I checked, I don't physically browse the internet any different than anyone else—evidenced by the fact that Blackbird UI looks exactly like Firefox (both are based around Mozilla), except, you know, with a black color scheme. And great, it comes preloaded with a bunch of bookmarks that might be of interest to the black community. But I'm pretty sure the same thing can be accomplished with an effectively marketed website (black people DO know how to use Google, after all. Shocker!).

Maybe 40A, Inc. meant well with Blackbird, but it comes off as a lazy marketing ploy that plays on the emotions of people who are (admittedly) still marginalized when it comes to the online world. And playing along with the notion that blacks and whites (or anyone, for that matter) can't enjoy any of the same things, is the same retarded line of antiquated, ethno-centric thinking that the internet is supposed to destroy. Blah. [Blackbird]

So Firefox 2.0 brings several changes to the Web browser that open source built. Some of the ones you'll immediately notice include:

•New visual theme. Yup, the 'fox looks different all right. Hooray (?)

•Built-in inline spell check. Handled by an extension before, spell check is now bolted onto the Web browser.

•Tab enhancements. Each tab now has an "X" in the top right corner instead of the one "X" in the tab bar. New windows now automatically open in a new tab rather than a separate window.

•Session restore. So far, I've only seen this work after a crash, but basically Firefox remembers all the tabs and windows that were open when things go haywire.

•Better RSS handling. Now you can subscribe to your favorite RSS feeds using either Firefox's built-in reader, a Web service (like Bloglines) or a stand alone application.

Many on the Interweb claim that these enhancements are nothing more than feature creep at its finest. Any opinions on this? – Nicholas Deleon

Download Page [Mozilla.com]

The Opera Web browser comes as a cartridge for either the original Nintendo DS, seen here, or for the newer DS Lite. The next territory it's expected to be released in is North America; the exact date is still unknown, however. – Nicholas Deleon

Nintendo DS Opera Browser released in Europe [SlashGear]