The people who live and breathe the Internet will all tell you the same thing: Firefox is the best Web browser for Windows and the Mac. Even after Microsoft played catch-up patty-cake with the release of IE7 earlier this year, Windows users who truly know the Web are continuing to choose Firefox.
The funny part is that it's not about features for Firefox users, it's about compatibility, customizability and convenience. In many ways, IE6 gave Firefox more competition because it was the de facto standard. That's no longer the case with Internet Explorer 7. Many enterprise users are finding that IE7 breaks this or that required Web site or Web-based enterprise application. A standard that's no longer standard is, to many, a lot less valuable.
In the end, Firefox's rich pool of third-party customizations puts it over the top. You can't tweak Internet Explorer 7's interface all that much. In fact, the excellent toolbar system from IE4 - IE6 is partially missing in IE7. You can't even uninstall many of the browser add-ons that are available for IE7.
No other browser comes close to Firefox' array of third-party customizations.
Size and performance
Opera is the anti-Firefox. It's all about features, features, features. That's so Nineties! Opera bristles with bells and whistles most of us are never going to use. That's only part of the reason, though, why it has such a clunky interface. Opera's designers are great at thinking small, but not great at thinking small and smooth. The rough edges are apparent everywhere you look.
Opera's only true advantages are small size and solid performance. But get this: Opera's International edition (which is what came down when I clicked the main download link for Opera 9.02 on the Opera home page) is 6.27MB, while the Windows version of Firefox 2.0 from the main download link is 5.62MB. So much for Opera being teeny-tiny.
Of course, that bloated pig, Internet Explorer 7, tips the scales at 14.78MB. No matter how you slice it, it's pushing three times the download size of Opera or Firefox.
Which one of these three browsers -- and the fourth in our roundup, Apple's Safari -- is fastest? I would submit to you that it just doesn't matter. They all perform in the same range, which is to say they're all pretty fast. There's no test that would be truly meaningful, because each loads different Web sites at different rates, depending on the coding used.
Security? IE sure needs it
What about security? IE7's aggressive security will interrupt you frequently with yellow bars and other prompts to deliver the same security that Firefox offers out of the box. If you want to feel like you're browsing from jail, be my guest. I prefer the feeling of freedom Firefox engenders.