The Mozilla Foundation celebrated the arrival of Firefox 3 with a worldwide party and an attempt to set a new world record for the most downloads ever of a single software programme. The record attempt may have been silly, but there is something to celebrate.

Firefox 3 is the best Web browser I've ever seen. And I've been using the Web since before there were Web browsers .

As far as I'm concerned, Firefox has been setting the standard for Web browsers since it first appeared in 2004 . At the time, Microsoft 's Internet Explorer ruled the Web, and it did a lousy job. But unless you were savvy enough to try alternatives such as Opera -- or were still hoping that Netscape would get its act together -- you were stuck with IE.

Firefox was a breath of fresh air. It was everything that IE wasn't. It was secure and fast, and it supported extensions to transform the browser from a mere utility to the heart of the modern-day computing experience.

For a while, though, Firefox went into a decline. Mozilla kept adding features, but at the expense of memory, stability and performance. At the same time, Microsoft had finally been forced to improve Internet Explorer. Firefox was still better, but it was no longer that much better than IE 7.

With this latest version, however, Firefox is back on track.

Resolving memory issues

For example, one of the ways that Firefox 2 annoyed people was the way it handled memory. The longer their browsers were open, and the more pages were loaded, the more memory was used. The result for some users -- especially those whose systems didn't have much memory to begin with -- was that performance would drop to a crawl.

They also lost stability. With Firefox 2.x, I was averaging a complete Firefox failure -- all browser windows either freezing or closing down -- once every two days.

What was happening was that Firefox's bad memory management habits were zapping me. For example, Firefox 2.x used different-sized chunks of memory. Then, as it constantly grabbed and released memory, its memory map began to look like a beaten-up jigsaw puzzle. Here a hole, there a troublesome spot where someone had torn off part of a piece to make it fit, and so on.

In addition, Firefox 2.0 kept full-size copies of images in memory. When you displayed a JPEG or any of the other compressed picture formats, Firefox kept the full-size uncompressed images in memory even if you weren't currently looking at them. Since a single 100k image can eat up a megabyte-plus of memory, this old way of handling images can waste memory quickly.

Mozilla's engineers seem to have fixed that -- or at least improved it -- in Version 3. Now, if you're not looking at an image, it's been saved in memory in its original compressed format. They've also worked on the memory map issue.

Firefox 3 is now using expiration policies in its memory caches. The developers' thinking is that if you haven't retrieved a previously viewed page in half an hour or so, the savings in memory by dropping the page from your cache are more important than the small possibility your page will load faster if you retrieve the stale document. (For more explicit information on how memory issues have been tweaked in Firefox 3, a good resource is this blog entry by Mozilla developer Stuart Parmenter.)

The result is that, regardless of any other improvements, Firefox 3 is faster and more stable than its predecessor.

I found that, on average, opening and closing tabs on Firefox used up about 5% more RAM per browser tabbing session compared with Firefox 3. And in the weeks I've been running Firefox 3 on multiple systems on the same exact same PCs doing the same work as I was doing with Firefox 2.x, I haven't seen a single freeze-up.


Besides the memory improvements, I found Firefox to be both faster and more stable than its predecessor for other reasons.

Thanks to the vastly improved Gecko 1.9 Web rendering platform, Firefox makes complex pages -- like Computerworld 's own front page, with its text, graphics and animations -- pop, rather than be painted, on the screen.

To test that, I looked at a group of pages, first on Firefox and then on 3.0. (In all cases, I cleared the cache first.) I saw a 20% to 35% reduction in the time from when a Web page was summoned to when it completely appeared on the screen.

Next up, I tested Firefox 3 for its compliance with Web standards such as CSS, JavaScript, SVG and XML with the Web Standards Project's Acid3 test.

Here Firefox 3 scored 71, which isn't exactly a prize-winning rating; the latest version of Safari for the PC, Safari 3 .1.1, scored 87. On the other hand, the other browsers I tried, such as IE 7 and IE 8 beta 1, turned in even worse results. Since Safari's security could well be described with the word awful , I'll stick with Firefox.

For practical purposes, the only Web pages that are likely to give you trouble are the same ones that always have: Web pages that were designed specifically with Internet Explorer and ActiveX in mind. But I wouldn't worry too much: In the months I've been using Firefox 3, first as a beta and then as a release candidate, Firefox had no trouble rendering any of the thousands of Web pages I visited.


Often, when it comes time to look at a product's new features, I end up writing what amounts to a laundry list of functions that no one is ever likely to use in the real world. That's not the case with Firefox 3.

For example, the protection mechanisms against malware and cross-site scripting actually work. Firefox warns you before you enter sites that have been known to carry malware -- you can continue, if you really want to, but at least you'll know you're heading into trouble.

Protection against cross-site scripts -- a.k.a. Web forgery -- goes farther. Firefox 3 won't even show you content that seems to be coming from an illegitimate site or is trying to play break-in games with JavaScript. You can still force Firefox to show you the site's content -- but on your own head be it.

Firefox 3 also gives you more information about the sites you visit than earlier versions did. The drop-down listing of possible addresses that appears when you start typing in an URL has been enhanced to be easier to read and show more information.

Clicking on the favicon -- the tiny icon to the left of an URL address -- will give you a window that, hopefully, will show such information as who owns the site, what cookies have been set and other elements that may have been delivered. Unfortunately, that feature isn't all that useful yet -- few Web sites bother with identity information -- but it's got potential.

Another nice feature is that when (as is so often the case) you come across a Web site with an SSL security certificate that's not quite right, Firefox displays enough information about the certificate so you can make an informed decision about whether you want to trust the site or not. It's still an error message, but at least now it's an easy-to-understand error message.

Firefox now asks if you want to save your password only after you've successfully logged in to a Web site. For those of us who always type in passwords wrong the first time, this can be darn handy.

Bookmarking has also been improved. For example, the new Smart Bookmarks folder, which appears in your bookmarks toolbar, automatically picks up and lists your most-often visited pages. Firefox 3 also enables you to add keyword tags to your bookmarks and then sort your bookmarks by these tags.

On a purely aesthetic basis, Firefox will now adjust its look to match that of your Mac OS X , Linux or Windows operating system. This worked perfectly on my XP, Vista, Mac OS X 10.4 Tiger and Linux systems running both KDE and GNOME. It sounds small, but I found the overall effect to be surprisingly easy on my eyes.

Care with extensions

If you can't live without a particular browser extension, you'll want to hesitate before immediately upgrading to Version 3. Firefox's new extension subsystem insists that any extension provide a secure Web site for updates; it also changed some of the APIs. Extensions that don't currently support these changes (as of this writing, this included Google Toolbar ) won't work with Firefox 3.

On the other hand, you may find that you don't need many extensions commonly used with Version 2. For example, with the new Firefox you can increase text size, so you may no longer need extensions like NoSquint.

Firefox also finally has an improved download manager, which supports interrupted download resumption, so you may not need a third-party download manager. In addition, Firefox can now register Web-based protocol handlers. This means that you can now open mailto and iCal links with your Web application of choice without adding an extension.

In other words, if you don't absolutely need incompatible extensions, there's a lot to be said for upgrading today.

Firefox has also improved its help system. It now reaches out to the Firefox support Web site for help information. Everyone has the experience of searching for help, only to find that the on-PC help is hopelessly outdated. With Firefox 3, you can always get to the most current information.


Nothing is perfect in this world. Still, when it comes to Web browsers, Firefox 3 is as good as they come. Certainly, compared with the forthcoming Internet Explorer 8 and the security problem-prone Safari, Firefox 3 is the standout browser for 2008.

Since Firefox first appeared on the scene in 2004, it has set the standard for Web browsers. Not only did it break Microsoft's iron grasp on Web browsing, its very existence forced Microsoft and the other browser companies to up their game. All of the Web browsers are far better than they were before Firefox came along.

Now Mozilla's open-source developers have set the bar even higher. Firefox 3 is the best of the breed.