Firefox Beta and Developer Edition
Release Notes

Improved warning pages for certificate errors and untrusted connections

Enable H.264 if system decoder is available

Enable WebM/VP9 video support on systems that don't support MP4/H.264

Windows XP and Vista screensaver doesn't disable when watching videos (Bug 1193610)

Firefox has removed support for the RC4 cipher

To support unicode-range descriptor for webfonts, font matching under Linux now uses the same font matching code as other platforms

Firefox will no longer trust the Equifax Secure Certificate Authority 1024-bit root certificate or the UTN - DATACorp SGC to validate secure website certificates

Use a SHA-256 signing certificate for Windows builds, to meet new signing requirements

Right click on a logged object in the console to store it as a global variable on the page

Visual tools for Animation:

• View/Edit CSS animation keyframe rules directly in the inspector
• Visually modify the cubic-bezier curve that drives the way animations progress through time
• Discover and scrub through all CSS animations and transitions playing on the page
• Learn more: http://devtoolschallenger.com/

Visual tools for Layout and Styles:

• Display rulers along the viewport to verify size and position and use the measurement tool to easily detect spacing and alignment problems
• Use CSS filters to preview and create real-time effects like drop-shadows, sepia, etc
• Learn more: http://devtoolschallenger.com/

New memory tool for inspecting the memory heap

Service Workers API

Built-in JSON reader to intuitively view, search, copy and save data without extensions

Jump to function definitions in the debugger with Cmd-Click

WebSocket Debugging API and add-on

The rule view now displays styles using their authored text,
and edits in the rule view are now linked to the style editor

Add-on signing enforcement