Mozilla Firefox beta specifications

Browsers: Chrome Extensions; Firefox Add-ons & Plugins; Internet Explorer Add-ons & Plugins; Newsreaders & RSS Readers; Offline Browsers; Other Browser Add-ons & Plugins; Web Browsers

When opening a new tab, users are now presented with their most visited pages
The default home page now has quicker access to bookmarks, history, settings, and more
SPDY protocol now enabled by default for faster browsing on supported sites
Restored background tabs are not loaded by default for faster startup
Smooth scrolling is now enabled by default
72 total improvements to Page Inspector, HTML panel, Style Inspector, Scratchpad and Style Editor
The column-fill CSS property has been implemented
Experimental support for ECMAScript 6 Map and Set objects has been implemented
Support for the CSS3 background-position property extended syntax has been added
The :invalid pseudo-class can now be applied to the element
The CSS turn unit is now supported