By itself, Firefox is a lean and fast browser (see Firefox 1.0 review), but it lacks some of the functions that we've come to take for granted from Microsoft Internet Explorer. It's easy to remedy that situation with small add-on extensions. Extensions can do loads of tasks, from blocking pop-up ads to playing card games—and even viewing a Web page as if it were in IE—so they can make Firefox a versatile and customizable platform for your browsing activities. But where to start? Which extensions are worth downloading and installing? We evaluated dozens of extensions and present the best 15 for your perusal. It's easy to add them; just go to the Tools | Extensions | Get More Extensions menu to get started.
About site 0.1.1 provides a great deal of site information through tabbed windows. Accessed by right-clicking anywhere on a page, this extension shows Alexa traffic information, Google Linked or Google Related information, performs a Whois query, searches Technorati for references, or searches the Internet Archive Wayback Machine for stored copies of pages. This extension is extremely helpful for those who want to learn more about a site or conduct a search based on the information contained on a site.
Adblock 0.5.2 is an ad-blocking extension that uses content filtering and URL blocking to prevent Firefox from displaying unwanted images. From the Tools | Adblock | Preferences screen it is easy to add new terms to block, including wildcards and file types. It's possible to use Regular Expressions (text patterns that can match various text strings) as new terms. You can also right-click on ads and choose to block them from the context-sensitive menu.
Bandwidth Tester 0.4.1 provides a menu option under Tools for testing the bandwidth of your Internet connection. The extension downloads four files of varying size and calculates bandwidth based on average download time.
Cards 0.16.1 offers 27 different solitaire games, from Aces Up to Yukon, accessible via the Tools | Cards menu. Unfortunately, it doesn't explain any of these games, so you won't be learning much about the world of solitaire. All games are played in a new pop-up window that won't interfere with your browsing.
Clusty Toolbar 1.0.2 helps you find information quickly and easily. It's possible to search and cluster results from multiple search engines, as well as obtain encyclopedia information (from Wikipedia), dictionary definitions, and even shopping and gossip, doing it all either by selecting a word or phrase and right-clicking to display the context-sensitive menu, or by typing it in the search box. Mini-Mode saves valuable screen space by eliminating the toolbar and keeping Clusty's functionality on hand.
ColorZilla 0.8.2 provides a color reading from any point in your browser that can easily be pasted into another program. The most helpful feature lets you zoom in on the page you are viewing (though still not as well as the Opera browser does natively) and measure distances between any two points on the page. Once zoomed, you can pan the page using Alt+Shift+Drag. All of this functionality is accessed by right-clicking on the ColorZilla icon at the left side of the browser-status bar and selecting the ColorZilla submenu.
DictionarySearch 0.7 allows you to select a word, right-click on it, and choose Define. A definition provided by Dictionary.com then appears in another tab. This is a very easy way to learn the meaning of new words from within Firefox.
ForecastFox 0.5.8 is a must for weather buffs. This extension provides weather-report icons within the application (you can customize where they should be placed). There's one icon for current conditions, another for today's forecast, and a third for tomorrow's forecast from weather.com. When you mouse over the icons they give you more precise weather information. Setting up profiles for different locations lets you quickly toggle between forecasts and make the most of this extension.
FoxyTunes 1.1 places remote controls for the media player of your choice within Firefox so you can control your music without leaving your browser. The controls appear on the status bar or one of the toolbars, so no space is wasted. You can pause, forward/reverse, play, adjust the volume, and see what's playing. There's also an alarm clock and a sleep timer. This is a must-have extension for users who regularly listen to music while browsing the Web.
GoogleBar 0.9.0.30 brings the popular Google Toolbar to Firefox. Search the Web or the current site, highlight search terms, and get page info, all from a single toolbar.
Google Preview 0.8 shows a small snapshot of each Google result for a search. This can save time when you're deciding where to turn for more information.
MapIt! 0.4 lets you query MapQuest for an address quickly and easily. Simply right-click anywhere in the browser window, choose MapIt! from the context-sensitive menu, and then fill in the form that appears on the top left of your screen. It would be better if MapIt! could search for addresses in highlighted text and map them, but the extension does save you the trouble of leaving the Web page you're on to go to MapQuest. Maps load in the background in a new tab.
ScrapBook 0.12.0 allows you to collect clippings (really whole Web pages) from the Web sites you visit. It organizes the clippings and saves them to disk along with your own comments and annotations. The original URL of the clipping is also stored so you can revisit the site for more information. You can search notes and clippings. An indispensable tool for conducting research using Firefox.
Tabbrowser Preferences 1.1.1 gives you greater control over Firefox's tabbed window interface through the Tools | Options | Tabbed Browsing menu. Tabs can appear at the top or bottom of the browsing window and can be locked so that all clicked links open in a new tab. New tabs let you open URLs from the URL bar and searches from the search bar. It can even force every new tab to load your homepage.
xMirror 0.1.1 adds a selection menu for alternate extension-download sites to the Extensions Manager. No need to restrict yourself to just the one.