July 01, 2009

The just-released version 3.5 of Firefox is a winner, offering significantly faster Web browsing, better tab handling, a host of interface tweaks and, like just about every other browser on the planet, a "porn mode." If you already use Firefox you'll want to upgrade right away. If you're not a Firefox user, this version represents a very good opportunity to give the browser a test run.

For many people, the browser wars are all about one thing: speed. There's no doubt that version 3.5 of Firefox is significantly faster than version 3. Pages load noticeably more quickly for a number of reasons, not least because Mozilla built a new JavaScript engine called TraceMonkey for this version of Firefox.

How much faster is open to debate. Mozilla says it ran the industry-standard SunSpider JavaScript Benchmark, which measures how quickly browsers render JavaScript, on versions 2, 3 and 3.5 of Firefox, and asserts that the newest version is more than twice as fast as Firefox 3 and more than ten times as fast as Firefox 2 on the test. Other testers have reported similar results.

Of course, rendering JavaScript quickly doesn't necessarily mean that all Web pages load faster. Microsoft, for example, argues that for most Web pages, other kinds of speed-ups are more important than rendering JavaScript quickly. I'll leave that debate to Microsoft, Mozilla and other browser makers. But putting aside any speeds-and-feeds specs, I can tell you that from the user experience, Firefox 3.5 is lightning fast -- it seems to me about comparable to the recently-released Safari 4.0 for the Mac.