Now a mature and capable product, Mozilla's Firefox has emerged as the de facto alternative to Microsoft's dominant but faltering Internet Explorer (IE). The latest version, Firefox 3.5, was originally planned as a minor update and was going to be branded accordingly as Firefox 3.1. But Firefox 3.5 is at least as momentous as its predecessor, Firefox 3, thanks to some important improvements to the product's support of web technologies, performance, and security. Debates about whether this is a major or minor update are pointless, however. If you're a Firefox user, you're going to want to upgrade, and if you're not, this browser certainly has enough going for it to convince you to at least give it a shot.

Private Browsing mode

In a bit of catch-up with IE 8 (see my review) and Google Chrome (see my overview), Firefox 3.5 includes a new Private Browsing Mode feature, which has been jokingly referred to as "porn mode" elsewhere. As with the comparable functionality in other browsers, Private Browsing Mode allows you to browse the web privately; that is, while in this mode, Firefox will not retain any data about the web sites and pages you visit. This data includes your browsing history, form and search bar entries, passwords, the list of files downloaded, cookies, and cached temporary Internet files. Saved bookmarks and downloaded files are retained after Private Browsing Mode is ended.

Mozilla Firefox 3.5
In Private Browsing mode, Firefox 3.5 does not store browser history, search history, download history, web form history, cookies, or temporary internet files.

Private Browsing Mode works as advertised but is not as convenient as IE 8's InPrivate Browsing feature because Firefox requires all existing browser windows and tabs to be closed so that the application can enter Private Browsing Mode. IE 8, by comparison, simply opens a new window that operates in InPrivate Browsing mode, allowing you to mix and match.

Additionally, Firefox 3.5 provides a handy way to hide your browsing history and other data on the fly. Just click Tools, Clear Recent History, and you'll get a handy dialog for determining how far back to wipe.

Mozilla Firefox 3.5
Clear Recent History lets you hide your tracks on the go.

Support for new and emerging web technologies

The most notable new features in Firefox 3.5, perhaps, are its most forward looking. The browser now offers better support of next-generation web standards like HTML 5, including emerging web-based Ogg video and audio support that will negate the need for plug-ins. (Assuming, of course, anyone bothers to use these formats.)

Mozilla Firefox 3.5
Support for HTML means you can view some web video without plugins. (Original video here.)

Firefox 3.5 also supports location aware browsing, which can be used by web sites to help you find services and information near your physical location. (It's optional of course.)

Performance improvements

Thanks to its TraceMonkey JavaScript engine, Firefox 3.5 boasts significant performance improvements over its predecessors, especially with complex web applications. Mozilla claims that Firefox 3.5 is twice as fast as Firefox 3, and ten times faster than Firefox 2.0, on such web apps. I can't corroborate those Apple-esque numbers, but Firefox 3.5 performs ably in my own tests. It's also still a bit of a memory hog, routinely taking up 2-3 times as much memory as IE. But on today's PCs, that's much less of an issue than some make it out to be.

Availability

Mozilla Firefox 3.5 is available on all the major platforms--Windows, Mac, and Linux--and in over 70 different languages. You can find out more on the Mozilla web site.

Final thoughts

While I'm not too excited about Firefox's bland UI, especially in Windows Vista/7--a UI that continues largely unchanged from Firefox 3--Mozilla's latest entry is a solid and viable browser for users of all kinds. I've been using IE 8 a lot lately, but I still use Firefox very regularly, and Firefox 3.5 is an easy fit. The browser's main strengths--its extensibility, compatibility, and performance--continue forward in version 3.5 and are augmented with improvements. Mozilla seems to be on a fairly slow development schedule--it would appear glacial if it weren't for Microsoft--but each release is reliable and trustworthy. There's not much new here, but it's Firefox, and it always comes highly recommended.