Firefox 3.1 may only be a point release -- from 3.0 to 3.1 -- but its just-released Beta 2 version is a good indication that the final release will be a must-have upgrade for anyone using Firefox.
Beta 2 (now available from Mozilla) unveils the browser's most important new feature, Private Browsing, a privacy feature that automatically deletes all traces of a browsing session. In addition, the new beta turns on a feature designed to make the browser up to 40 times faster (at least, according to Mozilla).
Browsing in private
The most important new feature in beta 2 is the addition of Private Browsing -- the same feature that is called Incognito Mode in Chrome, and InPrivate Browsing in Internet Explorer 8. All traces of your browsing session are deleted when you use Private Browsing -- your browsing history, temporary Internet files, search history, download history, Web form history, and cookies. (For obvious reasons, it's popularly known as "porn mode.")
To launch a Private Browsing session, choose Tools --> Private Browsing. When you do that, you'll get a warning that Firefox is going to close all of your current tabs to launch a Private Browsing session.
Select Start Private Browsing, and from then on, the history of your session won't be kept. The only indication that you're using Private Browsing are the words Private Browsing in the title bar of your browser. To exit Private Browsing and return to your normal session, select Tools and uncheck the mark next to Private Browsing. Your previous Firefox session will be restored -- any tabs you had opened before you launched the Private Browsing session will open automatically open.
When using Private Browsing, you'll need to keep in mind that the feature doesn't quite erase all the traces of the browsing session. If you add a bookmark during a Private Browsing session, for example, that bookmark stays there, even when you exit Private Browsing and start Firefox normally. The same holds with downloads -- those stay on your hard disk. However, the download history of the session disappears.
The biggest problem with Private Browsing is that you won't be able to have a private browsing session at the same time you have a normal one, something that both Internet Explorer 8 and Chrome let you do. Let's say, for example, you're running one instance of Firefox, and want to also run a Private Browsing session. If you launch a second instance of the browser, then choose Tools --> Private Browsing, Firefox will only allow the Private Browsing instance to run --- it shuts down the other instance.
Faster browsing and other tweaks
Beta 2 adds another feature aimed at protecting your privacy -- it lets you erase your browsing history, cookies, download list, and other browser traces from the last hour, two hours, four hours, today -- or all of your browsing history. In previous versions of Firefox, you could delete all of your history or none.
To use the feature, you select Tools --> Clear Recent History or Ctrl-Shift-Del. From the drop-down list, choose the time period for which you want to delete your traces, and uncheck or check the specific traces you want deleted. Then click Clear Private Data.
As I worked with it, the beta certainly seemed zippier than previous versions, but further testing will be required to see how much faster it actually is.
In addition, this beta supports "Web workers" threads, a specification that lets Web-based applications run background processes. This should speed up Web-based applications, as long as developers take advantage of it.
Firefox has killed a feature that it had introduced in Beta: the Ctrl-Tab function, which showed thumbnails when you cycled through open tabs. According to its release notes, Mozilla says it pulled the function "based on feedback from users." However, users who want to use it with the current version of Firefox need not fret, because that function was based on an existing Firefox add-in called Ctrl-Tab.
Also new to Beta 2 is support for the <video> and <audio> tags that let you play media from directly within Firefox -- as long as the page uses the appropriate tags. If you go to the same page using Firefox 3.0, you'll see instead the error message: "Sorry, your browser does not support the <video> element."
Improved tab handling and Smart Location Bar
This version of the beta leaves in place a number of new features that were introduced with Beta 1 -- notably, changes to tab handling and the Smart Location Bar features. Starting with Beta 1, you can "tear" a tab from the tab bar by dragging it away and create a new, separate window out of it, something that Chrome allows, as well as other browsers such as Maxthon and Opera. Similarly, you can recombine tabs, and drag and drop tabs between instances of Firefox.
There's one more minor change as well --- there's now a + symbol at the far right of your tabs, which when clicked upon opens a new tab.
Beta 1 (and Beta 2) also make a nifty improvement to the Smart Location Bar (which some call the "Awesome Bar"). Normally, when you type text into the Awesome Bar, it shows you a drop-down list of URLs you've recently visited, as well as URLs from your bookmarks and narrows down the list as you type in more text. With Firefox 3.1, you can control the Awesome Bar and the results it displays by adding special characters to the end of what you type. You can have the Awesome Bar only display results from your history list, results from your bookmarks, results from the URL itself, or results from pages you've tagged. For example, to only display results from your history, you'd type in your search terms and then a space, followed by the ^ symbol.
The bottom line
Beta 2 of Firefox 3.1 is fast and stable and incorporates two important changes to the browser: a private browsing mode, and a sped-up rendering engine. I used it without problems or crashes on two different PCs. Those who want to see the future of Firefox would do well to download it now. When the final version is released, it will be a must-have download.