Many of the "new features" were already available as extensions before, but there's a substantial difference between making a feature available as an extension and building it into the browser. While savvy users will seek and find (or even write) extensions to satisfy their every whim, the Mozilla folks are trying to reach a broader audience -- an audience that by and large won't assume that it can get phishing protection, spell checking, or additional tab features by adding more software to their browser.
The new release includes a few subtle look and feel changes, but nothing dramatic or even very noticeable. I suspect that if you swapped Firefox 2.0 for Firefox 1.5 on most average users' desktops, they wouldn't notice the new icon set or theme changes.
One thing that users will notice right away, or at least I did, is Firefox's spellcheck feature. When you are writing an email using Gmail or another Web mail client, or composing a blog entry, or just posting a comment to a forum, Firefox will provide the familiar red squiggly when a word is misspelled or not in the dictionary. Right-clicking on the word will bring up a context menu with spelling suggestions (if there are any) and an option to add the word to the dictionary. The spellcheck feature is fairly clueful -- it doesn't highlight email addresses or URLs in text fields, and isn't on by default for search fields and other text entry fields that you would usually not need to spellcheck.
Firefox 2.0 has been relatively stable throughout its development cycle, but I have had a few random crashes, and a few other occasions to test Firefox's session restore feature. In previous releases, if Firefox crashed or if you restarted Firefox after installing a new extension, you would lose Firefox's state -- meaning that if you'd been doing some research on Google and had dug up some useful sites, you'd have to go through that whole process all over again.
Now, Firefox has a session restore feature built into the browser. After a crash or restart after installing extensions, Firefox gives you the option of starting over with a new session or starting with the old session. Prior to 2.0 you could add this sort of functionality with a Firefox extension, which also provided the ability to save session information anytime you quit the browser. Firefox 2.0 only offers to restore the previous session state in the event of a crash or restart after installing an extension or update -- you aren't prompted to save the session when you quit Firefox normally.
Managing extensions in Firefox - click to view
What's extra-spiffy about the session restore is that Firefox can even remember user input in some text fields, so if you're composing a blog entry and the browser crashes, or you just forget about that 600-word entry and restart Firefox after installing a new extension, Firefox may be able to restore your text as well as the browsing history.
Speaking of installing extensions, Firefox 2.0 revamps extension and theme management, and bundles them both into "Add-ons" now. It also adds the ability to uninstall extensions, and makes the whole process of managing extensions easier.
Most, if not all, of your favorite extensions should work with Firefox 2.0. I use a number of extensions, and most of them were working with Firefox early in the beta release cycle. The only holdout was the del.icio.us extension, which seems to have been updated for Firefox 2.0 shortly after the 2.0 release.
Better feed support
Firefox 2.0 builds on support for RSS and Atom feeds by adding a feed preview and the ability to subscribe to feeds as live bookmarks, or through Web services like Bloglines, My Yahoo!, and Google Reader. Just click on the orange feed icon in the URL bar and Firefox will provide a preview of the feed and the subscription options.
Firefox feed preview - click to view
If you use one service religiously, you can choose to always use a specific service to subscribe to a feed. For example, since Google revamped Google Reader, I've been using it almost exclusively. Firefox 2.0 integrates so well with it that it's just as good as a desktop application.
The next time you set a bookmark, you might want to pay close attention to see if the site offers a microsummary. Firefox 2.0 now includes support for site microsummaries, or Live Titles, which you can see when you hover over a bookmark. When you set the bookmark, you'll see a drop-down arrow next to the Name field. The default is still the site's title, but you can also choose from one or more microsummary previews if they're available.
Adding bookmark with Live Title - click to view
For instance, Woot.com provides microsummaries that highlight its deal of the day. Rather than seeing the site title when you look at the bookmark, you can see the current deal. This is a nifty feature, but pages with support for microsummaries are still few and far between, though it is possible to create your own if your site of choice doesn't offer a microsummary.
The Moz folks have also beefed up the search function in Firefox 2.0, so that you get search suggestions as you type. Just start typing in the search box in Firefox's upper right corner. Assuming you're searching for something that has been searched for before, you should see a couple of useful suggestions after you've typed in a letter or two.
Another much-touted feature in Firefox 2.0 is the phishing protection feature. Firefox can grab a list of known phishing sites from Google and alert users when they stumble onto a site that is probably not what it's trying to appear to be. It works well enough as far as I can tell, but I've only had a handful of honest-to-goodness phishing scams sent to my Gmail address lately to be able to test the feature. (Ironically, the Mozilla phishing test site didn't seem to be working when I tried it.)
Firefox 2.0 includes the ability to re-open closed tabs. One might say that Firefox had to introduce the undo tab close, since the placement of the tab close buttons makes it easy to accidentally close a tab when you're trying to click on another to bring it into focus. Actually, this happens less than you might expect, since the close button is only present on the tab that's in focus at the time -- you can't accidentally close the adjacent tab when bringing it into focus unless you double-tap it when clicking.
The tab bar now sports a menu of open tabs on the right side of the browser, so when tabs get too crowded, you can click the menu for a full list of windows. If things get really crowded, Firefox will spawn arrows on either side of the tab bar so you can cycle between tabs, rather than trying to squish so many tabs into the tab bar that their titles are illegible.
Firefox 2.0's new tab layout - click to view
After using Firefox release candidates and the final version, I have run into only one consistent bug worth noting. By default, Firefox is configured to open links that would spawn a new window in a tab instead. This in itself isn't a glitch, but the fact that Firefox keeps resetting this behavior after I specifically tell it to open the links in a window rather than a tab is annoying. I'm not sure what triggers the reset, but each time I check in Firefox's Tab preferences dialog, the radio box for "a new window" is still checked. Changing this to "a new tab" and then back again solves the problem, but only for a little while.
Where's Firefox going?
I had the chance to talk to Mozilla's phenomenologist (yes, that's really his title), Mike Beltzner, about the 2.0 release. Beltzner extolled the new features in Firefox 2.0, talked about Firefox parties celebrating the new release, and also talked about things to come in releases after 2.0.
Beltzner says that Mozilla developers are looking at getting rid of the requirement to restart the browser after you install and uninstall extensions. Due to the way Firefox works now, requiring extensions to be registered at startup, that's not possible with the current codebase.
He noted that Firefox users may be see more frequent experimental builds of Firefox, with interesting features enabled through extensions or new builds, courtesy of Firefox Labs. There are no mutant Firefox builds available yet, but Beltzner says experimental Firefox features should be available from the labs in the not-too-distant future.
If you'd like to live on the bleeding edge of Firefox development, there's always the Firefox 3.0 codebase. You can follow Firefox 3.0 planning and grab nightly builds of Firefox 3.0 -- though they're not likely to be of the same quality as final or even beta releases of Firefox. In fact, the most recent nightly build I tried segfaulted immediately upon startup for me.
The current schedule, which may slip, puts a 3.0 release in May 2007, with feature freeze and the first beta scheduled for the end of February.