Firefox 44 发布，更新如下：

New

• 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

• In the animation-inspector timeline, lightning bolt icon next to animations running on the compositor thread

• Support the brotli compression format via HTTPS content-encoding

• Screenshot commands allow user choice of pixel ratio in Developer Tools

Fixed

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

• Various security fixes

Changed

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

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

• Firefox has removed support for the RC4 decipher

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

• Stricter validation of web fonts

• On-screen keyboard support temporarily turned off for Windows 8 and Windows 8.1

Developer

• 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

详情请看：release notes