Firefox 3.0.1

Improved Tabbed Browsing
Tabbed Browsing screenshot

We love tabs as much as you do, so Firefox 2 will open new web pages in tabs by default. Each of those tabs has its own close button, but don’t worry - if you accidentally close a tab, just go to the History menu to bring it back from the list of “Recently Closed Tabs.” You’ll never be crunched for space anymore, either. When you have too many tabs open to comfortably fit in a single window, scroll arrows will appear on either side, and a button on the right side will always show you an easy-to-read list of all your open tabs.
Spell Checking
Spell Checking screenshot

Sometimes you’re in a rush, and can’t remember if it’s “i” before “e” or the other way around. Firefox 2 has built-in spell checking to keep you from making any mistakes in your blog posts and Web-based email, so you can worry about more important things.
Search Suggestions
Search Suggestions screenshot

Some of the search engines in Firefox 2 can read your mind, and actually suggest search terms for what you’re looking for. Just start typing into the Search bar, and a drop down list of suggestions will appear. (Works for Google, Yahoo! and Answers.com.)
Session Restore

Losing your place while you’re doing things on the Web is a pain. Now, with Session Restore, if Firefox has to restart or closes when it comes back you’ll pick up exactly where you left off. The windows and tabs you were using, the text you typed into forms, and the in-progress downloads you had running will all be restored. You can even set Firefox 2 to always restore your previous session instead of loading a home page, so you’ll never lose your place again.