Firefox 3.6 adds speed and Personas but is it enough

The latest version of Firefox has some welcome, but not revolutionary, changes.

The just-released final version of Firefox 3.6 is a moderate improvement over previous versions -- it's faster and introduces a nifty new feature or two. But at heart, it's the same browser that has steadily gained market share against Internet Explorer for years.

This newest iteration shows all signs of continuing that trend, because it's opened up an even wider speed gap against Internet Explorer, better adheres to Web standards and adds a nice trick or two. Those who favor raw speed alone will still prefer Chrome, but Firefox is clearly superior to Chome when it comes to full-featured Web browsing.

I tested the latest version of Firefox on four machines: one running Vista, one running Windows XP, one running Windows 7 and one running Mac OS X Snow Leopard. I performed head-to-head testing of Firefox 3.6 against version 3.5, Chrome 4, Internet Explorer 8 and Opera 10 on a Dell Inspiron E1505 laptop with 1GB of RAM and an Intel Core Duo T2400 1.83Ghz processor, running Windows XP SP3.
It's all about speed


Here's the most important thing you need to know about Firefox 3.6: it's faster than 3.5. Using the SunSpider JavaScript benchmark, I found that version 3.6 was faster than 3.5 by 12%. It was nearly three times as fast as Opera and nearly four times as fast as Internet Explorer. But it still lagged behind Chrome by approximately 40%. I performed the tests three times for each browser and averaged the results, shown at the bottom of the page.

Even though Chrome beat Firefox by a wide margin when it comes to speed, Firefox appears to be better than Chrome when it comes to memory footprint when multiple tabs are open, at least according to my tests. With five identical tabs open in each browser, Chrome used 194.6MB versus 100.3MB in Firefox. That is partly by design, though, because Chrome uses separate processes for each tab, which leads to a larger memory footprint when multiple tabs are open.

The upside of this for Chrome (and for Internet Explorer 8, which uses the same technique), is that when an individual tab crashes, only that tab is brought down, and the browser itself remains running. With Firefox, when one tab crashes, it generally brings down the browser.
SunSpider JavaScript tests
SunSpider JavaScript benchmark results. Times are in milliseconds. Smaller numbers are better.

Firefox has always been bedeviled by poor memory management, particularly memory leaks. In this version, memory management remains somewhat problematic. When I launched Firefox 3.6 on my Vista machine with a single tab open to Google, it used 57MB of RAM. I opened five more tabs to different Web pages, and memory use grew to approximately 145MB.

However, after I closed down those additional five tabs, and stayed on my initial Google page, it was still using 81MB of RAM -- nearly a 50% increase in RAM use over when it launched. Clearly, the memory handling problem still needs to be resolved.
The most noticeable change: Personas

Although this new version of Firefox is mainly about speed, there is a nice new addition to the interface called Personas. Personas are essentially a way to add skins to your browser. Personas change the color and background graphic at the top and bottom of the browse.

Personas are slightly different than Firefox themes, which also change Firefox's navigation buttons, in that Personas leave the navigation buttons intact. Also, you don't have to restart your browser to add or change Personas, which you have to do with themes. Personas are certainly a nice extra, but they're far from groundbreaking.

You can find Personas by selecting Tools --> Add-Ons --> Themes and clicking Get Themes. (Yes, you get Personas by clicking Get Themes, which is quite confusing.)

When you install a second Persona, two buttons appear near the top of the browser: Undo and Manage Themes. Click Undo to revert to your previous Persona. Click Manage Themes and you'll be able to see all of your installed Personas, switch among them, and uninstall any you want.

Users of previous versions of Firefox were already able to use Personas, but only with an extension designed for that purpose. Now, with 3.6, the extension isn't required. However, the Personas Plus extension does make it easier to install, use, and manage Personas. Among other capabilities, it puts a small icon on the lower-left portion of your screen that lets you instantly switch themes and browser and install new ones.

Changes under the hood

Firefox has previously targeted support for HTML 5, and this newest release goes further down that road, with support for playing video in full screen without use of an add-on. Of course, very few sites use HTML 5 for this, so this is less-than-groundbreaking news. However, if full-screen video play ever catches on, it will be nice to have.

Firefox also now supports the Web Open Font Format (WOFF), which allows custom fonts to be downloaded on the fly from Web sites and displayed as the creators designed them. Again, though, this technology is not yet in widespread use.

Firefox 3.6 maintains a high level of compatibility with Web standards, as evinced by its results in the Web Standards Project's Acid3 browser test. It scores 94 out of 100, up slightly from the 93 scored by Firefox 3.5. It trails the latest versions of both Chrome and Opera, which each scored a perfect 100. Internet Explorer scores a lowly 20, but Microsoft claims that there are security problems in designing a browser that adheres to the acid test.

As with every new version of Firefox, not all extensions work with it immediately, and some might break, although if past experience is any guide, almost all extensions are ultimately upgraded to work with it. Mozilla claims that 80% of existing extensions will operate. My favorite extensions worked without a hitch, including Xmarks Bookmark Sync, Google Toolbar, the TinyURL extension and the list.it note-taking extension.

Firefox has also added a nifty new security feature -- the browser alerts you when a plugin, such as Shockwave Flash, is out of date. This is particularly important, because even if your browser itself is secure, an out-of-date plug-in can be a security hole through which malware crawls. Mozilla has also set up a Plugin Check page that will show you all of your plugins, alert you about which are out of date, and let you update any of them by clicking an Update button. This page works with earlier versions of Firefox, not just version 3.6.

The bottom line

This latest version of Firefox is clearly an evolutionary rather than a revolutionary release. Other than a notable speed improvement, not much else is of note. Personas are of moderate interest; the improved HTML 5 compatibility is of little help right now, and may or may not prove important in the long run.

Still, if you're already a Firefox user, upgrading is a no-brainer -- the speed boost alone is worth the upgrade. If you're not currently a Firefox user, the moderately interesting new features may not be enough of a draw for you to give it a try. But you may want to give it a spin just to try out browsing the Web at full speed.