For the brave and the bold, Mozilla has released the first public beta of its upcoming Firefox 4 web browser. The new browser, a 20.2 megabyte download (courtesy of VersionTracker), incorporates the following fixes and changes:
– Tabs are now on top by default on Windows only – Mac OS X and Linux will be changing when the theme has been modified to support the change.
– On Windows Vista and Windows 7 the menu bar has been replaced with the Firefox button.
– You can search for and switch to already open tabs in the Smart Location Bar
– New Addons Manager and extension management API (UI will be changed before final release)
Significant API improvements are available for JS-ctypes, a foreign function interface for extensions.
– The stop and reload buttons have been merged into a single button on Windows, Mac and Linux.
– The Bookmarks Toolbar has been replaced with a Bookmarks Button by default (you can switch it back if you’d like).
– Crash protection for Windows, Linux, and Mac when there is a crash in the Adobe Flash, Apple Quicktime or Microsoft Silverlight plugins.
– CSS Transitions are partially supported.
– Full WebGL support is included but disabled by default at this time.
– Core Animation rendering model for plugins on Mac OS X. Plugins which also support this rendering model can now draw faster and more efficiently.
– Native support for the HD HTML5 WebM video format.
– An experimental Direct2D rendering backend is available on Windows, turned off by default.
– Web developers can use Websockets for a low complexity, low latency, bidirectional communications API.
– Web developers can update the URL field without reloading the page using HTML History APIs.
– More responsive page rendering using lazy frame construction.
– Link history lookup is done asynchronously to provide better responsiveness during pageload.
– CSS :visited selectors have been changed to block websites from being able to check a user’s browsing history.
– New HTML5 parser.
– Support for more HTML5 form controls.
The Firefox 4 beta is available for free and requires Mac OS X 10.4 or later to install and run.
If you’ve tried it and have any feedback to offer, let us know in the comments