Firefox  3.6 Beta 4
* Changes to how we allow third party software to integrate with Firefox in order to prevent crashes.
* The ability to run scripts asynchronously to speed up page load times.
* More than 140 bug fixes from the last beta to improve performance, stability, security and features.
* This beta is available in more than 60 languages - get your local version.
* Users can now change their browser's appearance with a single click, with built in support for Personas.
* Firefox 3.6 will alert users about out of date plugins to keep them safe.
* Open, native video can now be displayed full screen, and supports poster frames.
* Support for the WOFF font format.
* Support for new CSS, DOM and HTML5 web technologies.