Firefox 4 Arrives, 2nd beta

The second beta release of the next version of Firefox is now available.

... Keep in mind, this is a pre-release version of the browser, and it may not be entirely stable. But it should be stable enough for daily use, and it will give you a heads up on all the new goodies coming in Firefox 4 when it’s officially released this fall.

Tuesday’s release has a number of new features, including support for CSS 3 transitions, better handling of retained layers on pages and a new feature in the add-ons manager that confirms when an add-on has been installed. There are also the requisite performance boosts and stability improvements, so if you’re running beta 1, definitely consider upgrading.

The feature sure to generate the most chatter is something new for Mac OS X users: a new tabs-on-top interface. Windows users got the tabs-on-top look as the default interface in beta 1 earlier this month. With beta 2, the change arrives on Macs. The new beta also enables App Tabs, a similar concept that lets you miniaturize the tabs for common web apps — e-mail, your calendar or other apps you use multiple times a day — and store them in the tab bar for quick access.

The move to tabs-on-top is a growing trend among browser vendors. It was popularized by Google Chrome, which has shipped with top tabs as the default since its birth two years ago. Reaction has been mixed — Opera now puts the tabs on top, and Safari tried the same thing in a beta release thing before abandoning it. And there are some within the Firefox user community who fear Mozilla is making the switch just to chase the latest design fad. ...

via Second Beta Release of Firefox 4 Arrives | Webmonkey | Wired.com.

Try it yourself: Get Firefox 4, Beta.  Here is a short list of what's new:

• Firefox 4 Beta 2 is available in 24 languages.


• Tabs are now on top by default on Windows and OSX - Linux will be changing when the theme has been modified to support the change.


• You can turn any tab into an "App Tab" by right-clicking on it and selecting "Make into App Tab" from the context menu.


• Web developers can animate content using CSS Transitions.


• Responsiveness and scrolling improvements from the new retained layers layout system.


• JavaScript speed improvements due to engine optimizations.


• Changes to how XPCOM components are registered in order to help startup time and process separation.

Recommendation: Wait for more plug-in support. Many plug-ins do not yet work with FF4, including download helpers, pdf managers, and others.