* Web standards improvements in the Gecko layout engine
* Added support for CSS 2.1 and CSS 3 properties
* A new tab-switching shortcut that shows previews of the tab you're switching to
* Improved control over the Smart Location Bar using special characters to restrict your search
* Support for new web technologies such as the and elements, the W3C Geolocation API, JavaScript query selectors, web worker threads, SVG transforms and offline applications.
* TraceMonkey. To enable it, you have to set the javascript.options.jit.content variable in about
:config to true, and restart the browser.
* HTML5 video and audio elements in Ogg Theora and Ogg Vorbis formats