Mozilla Firefox 47.0.1

Fixed

• Selenium WebDriver may cause Firefox to crash at startup

New

• Support for Google’s Widevine CDM on Windows and Mac OS X so streaming services like Amazon Video can switch from Silverlight to encrypted HTML5 video.
• Enable VP9 video codec for users with fast machines
• Embedded YouTube videos now play with HTML5 video if Flash is not installed.
• View and search open tabs from your smartphone or another computer in a sidebar
• Allow no-cache on back/forward navigations for https resources
• Latgalu [ltg] locale added. Wikipedia tells us there are 164,500 daily speakers.

Fixed

• Various security fixes

Changed

• FUEL (Firefox User Extension Library) has been removed. Add-ons relying on it will stop working.
• The browser.sessionstore.restore_on_demand preference has been reset to its default value (true) to avoid e10s performance problems. Because faster is better!
• The Firefox click-to-activate plugin whitelist has been removed.

Developer

• Web platform changes
• View, start,and debug registered Service Workers in the Service Workers developer tool
• Simulate Push messages in the Service Workers developer tool
• 'Start' button for service workers in about:debugging to start registered Service Workers
• Changes that can affect add-on compatibility
• Added support for ChaCha20/Poly1305 cipher suites
• Custom user agents supported in Responsive Design Mode
• Smart multi-line input in the Web Console
• Developer Information

HTML5

• cuechange events are now available on TextTrack objects
• WebCrypto: PBKDF2 supports SHA-2 hash algorithms
• WebCrypto: RSA-PSS signature support