Although Internet Explorer retains the lion's share of browser use, its competitors are gradually gaining favor. It's been a very long time since the browser market has been this unsettled and open to competition.

The good news for users is that every one of these top five browsers is exceedingly feature-rich, increasingly fast and easier than ever to use. The bad news is that it's become very hard to decide which to use.

That's why we decided to put the newest versions of the top browsers through their paces. Although Safari is available for Windows, and Opera and a beta version of Chrome are available for the Mac, we focused on the most popular configurations: Internet Explorer, Firefox, Chrome and Opera for Windows, and Safari and Firefox for the Mac.

We delved deep into their features, considered their speed and ease of use, and recommended what type of user each browser is most suited for. Finally, we chose overall winners for the Mac and Windows platforms.

What we've concluded has nothing to do with market share, and everything to do with which are the flat-out best, and why. So check out our reviews and recommendations, and let us know whether you agree.

Firefox 3.5 (Windows)

Of all the browsers, Firefox offers the best balance among speed, features, usability and extensibility. Because of this, it has been slowly eating away at the substantial lead enjoyed by Internet Explorer on Windows. Like Opera, Firefox is available for Windows, the Mac and Linux, so it is ideal for people or companies who use multiple platforms.

In my experience, Firefox doesn't feel as fast as Chrome or Opera, although it seems speedier than Internet Explorer. In Computerworld tests using the SunSpider benchmark suite, Firefox fell in the middle of the pack for JavaScript rendering.

Firefox 3.5 offers a great combination of performance, features and extras.
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Firefox may no longer be the browser to always introduce new features first (Safari, for example, introduced private browsing), but when it does include them, they always seem to be well thought-out and nicely implemented.

What may be the browser's greatest strength, though, is not its feature set as much as its massive ecosystem of free add-ons -- thousands of them, in every category imaginable. That, even more than the browser itself, is what sets it apart from its competitors.

Browser features

As with Internet Explorer, Firefox has all the features you want in a modern browser. There's anti-phishing, a pop-up killer, very good cookie handling, private browsing (a.k.a. "porn mode," which allows you to surf the Internet without leaving behind any trace of the sites that you have visited), excellent tab handling and more.

Firefox doesn't have much of a built-in RSS reader; its Live Bookmarks feature for handling RSS feeds is not particularly usable. However, add-ons solve the problem -- look for the excellent RSS reader called Sage.

What's most impressive about Firefox's features is not so much as what is there -- it offers fairly standard fare for browsers these days -- as the depth of those features and how they can be customized. Here's just one example: When clearing your browsing history and traces, you get control over which elements you want to clear, including your browsing and search history, form and search history, cookies, cache, site preferences and logons. And you can clear them based on time: all of them, those you've visited today, or those you've visited in the last four hours, two hours or one hour.

Firefox gives you control over which browsing history elements you want to clear.
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Similarly, dig deeply enough and you'll find out that Firefox lets you block images from being loaded on specific sites to speed up Web browsing. You can also turn off JavaScript and Java on specific Web sites.

The anti-phishing filter, like that in Internet Explorer 8, protects not only against phishing attacks but also warns you away from sites known to attack your PC. There's also a built-in spell checker.

Firefox also offers multimedia support (by supporting the HTML 5 audio and video elements) that lets you watch video and listen to music directly in a Web page without having to launch any plug-ins. The video is displayed by Firefox itself, and includes audio and video controls. You can also download the video and audio and save it on your PC. There's a catch, though: The Web page has to use HTML 5, and few do right now. So it may or may not become important in the future.

Interface and extras

Firefox's interface is about as simple as it gets: address bar, search box and menu across the top, browser area below. The look and feel is both good and bad -- good because of its familiarity, bad because the browser is beginning to look dated. Mozilla is making plans for a redesign, but its possible solution is running into some controversy.

Mozilla has said that upcoming versions of Firefox will do away with the menus, and instead use buttons as a way to access menus and features. Initially, Firefox had said it was planning on using a "ribbon" interface, which many people interpreted to mean the ribbon like the one used in Microsoft Office 2007 and 2010. Ribbon detractors were not pleased, and Mozilla quickly clarified that it was not planning to copy the ribbon interface.

In version 3.5, you get all the usual tab handling features, including the ability to undo tabs you've already closed. Particularly nice is the ability to see a list of closed tabs or windows and then choose which to open. (Select History --> Recently Closed Tabs or History --> Recently Closed Windows.) This works only for the current browsing session; the history does not carry over from session to session.

You can also tear off a tab and launch it into a separate window, or drag a tab from one browser window into another to combine them. One nice touch is that when you drag a tab to reposition it among other tabs, a thumbnail of the tab displays as you move it.

As with Internet Explorer and Chrome, the address bar, which Mozilla calls the Awesome Bar, does double-duty as a place to type URLs and a way to search the Web along with your history and bookmarks.

The bottom line

When it comes to balancing performance, features and extras, Firefox beats all other browsers, particularly because of the vast number of add-ons available for it. More than anything, that's what sets it apart. If you're the kind of person who like to fiddle and tweak your browser, and add extra capabilities, Firefox simply can't be beat.

-- Preston Gralla