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REVIEW: At first glance, it doesn't look that different from previous versions of the browser. And while there are nice improvements from a usability standpoint, there's nothing radically different for Web users.

But appearances can be deceiving. And with its release today, Firefox 3 is poised to usher in a new phase of Web browsing that will change how Web applications are built and delivered, and even how most of us use and think of the Web.

That's because most of the innovations of Firefox 3 are under the covers. Among the major new features in Firefox 3 are its offline capabilities and its ability to seamlessly interact with Web-based applications and services. With these enhancements, Firefox 3 makes it possible for sites to deliver applications and content that people can use—even when they aren't connected to the Internet—and that work with a browser in much the same way that traditional applications work with an operating system.

In this way, Firefox 3 may make it possible to finally deliver on the old promise of the Web as operating system. Because of these features, along with many welcome usability, security and performance enhancements, I am awarding Firefox 3 an eWEEK Analysts' Choice Award; as of this moment, it is clearly the top choice in Web browsers.

When users launch Firefox 3, they will see some small changes in the browser interface. By far, the biggest change is to the design of the back and forward buttons on the browser tool bar. The new interface essentially combines the two buttons into a single composite button shaped like a keyhole.

The back button (which tends to be used more than forward) is the larger portion of the keyhole. The forward button is smaller and to the right of the back button, and a dropdown menu to the right of the forward button lets users view all the pages they have browsed in that session (with the page they are currently on shown in bold type).

Also new is the favorites star in the address bar. A single click on this star bookmarks the page you are viewing, and two clicks brings up a pop-up window that lets you add tags for bookmarked pages. However, as this star button sits right next to the dropdown button that lets users view pages they have visited, frequent users of the dropdown may dislike the star button. I have accidentally clicked the star several times, often bookmarking pages I had no desire to bookmark.

Bookmark management has been boosted considerably. As mentioned, Firefox 3 includes tagging capabilities for bookmarks, making it possible to sort and manage bookmarks by topic. And a new smart folder in bookmarks includes automated groupings of sites, such as most visited pages, pages that have been starred as favorites and recently tagged Web pages.

Firefox 3 also includes many welcome enhancements to the browsing experience. Opening a group of tabs now appends them to existing tabs, rather than removing and replacing those that are already open. When lots of tabs are open, it is now easier to scroll through them, and when shutting down, Firefox 3 now asks if the user wants to save the open tabs and windows.

When logging into a password-protected site, Firefox 3 asks if the user wants the browser to remember the password after the user has successfully logged in, rather than prior to logging in when password mistakes may occur. In the download manager, it is now possible to get location information for files that have been downloaded and to pause and restart downloads. Also, progress information on downloads is now shown in the browser-status bar in the bottom right-hand corner of the browser window.

A big improvement to the address bar in Firefox 3 lets users begin to type a URL or even a search term, and the dropdown display in the address bar will show sites that have the same term—not only in the URL, but also in the Web page titles and headlines, automatically pulling information from the browser's history. This feature, which is also found in the latest version of the Opera browser, is a real time-saver when looking for specific Web sites and pages that you may have visited previously.

In Firefox 3, it is also now possible to use Web-based applications as helper applications within the browser. In tests, I was able to define Yahoo Mail as my main e-mail application and have Firefox automatically launch Yahoo Mail and create a new message when I clicked on mailto links in Web pages. This is an extremely useful feature—though it needs to be enabled by the specific Web-application developers.

Firefox 3 also includes a number of security enhancements. Clicking on the icon of a site in the address bar provides ownership information for secure Web sites. And when visiting a site that has an unsigned SSL (Secure Sockets Layer) certificate or a certificate that doesn't match the site domain, Firefox 3 puts up a much more noticeable warning page. Users who want to continue on need to add the site to an exceptions list (which can be somewhat of a hassle for those who use sites and applications with unsigned or nonmatching certificates). For sites that use Extended Validation certificates, the Firefox 3 address bar turns green.

Also new in Firefox 3 is a feature that attempts to identify known malware and phishing sites and provides strong warnings when users try to visit them.

A very welcome improvement in Firefox 3 makes it much easier to find and install extensions and add-ons for your Firefox browser. In the new add-ons dialog, users can now search and browse for extensions within the add-ons window itself, saving users from having to open a Web page to look for extensions on the Mozilla Web site. Add-on management also now includes the ability to manage classic browser plug-ins.

Firefox 3 now treats podcasts and videocasts as if they were a specific file type, making it possible to define helper applications that automatically launch when a user clicks on a podcast feed.

Firefox 3 also includes multiple performance and memory management improvements, and the results of my tests of the betas and initial tests of the final version's performance and memory management have been very good.

Overall, standards support in Firefox 3 is good, and in tests of the betas I had no problems accessing any Web sites. In the Web Standards Project's Acid tests, Firefox 3 passed the Acid2 test but not the more recent Acid3 test, where it scores behind the recent Opera and Safari releases.

As always, Firefox has excellent platform support and runs on Linux, Mac and Windows systems. This release also does a good job of using the interface conventions of these operating systems.

To download the free, open-source Firefox browser, go here.