What’s New
FIXED
20.0: Security fixes can be found here
NEW
Per-window Private Browsing. Learn more.
NEW
New download experience. Learn more.
NEW
Ability to close hanging plugins, without the browser hanging
CHANGED
Continued performance improvements around common browser tasks (page loads, downloads, shutdown, etc.)
DEVELOPER
Continued implementation of draft ECMAScript 6 - clear() and Math.imul
DEVELOPER
New JavaScript Profiler tool
HTML5
getUserMedia implemented for web access to the user's camera and microphone (with user permission)
HTML5
<canvas> now supports blend modes
HTML5
Various <audio> and <video> improvements
FIXED
Details button on Crash Reporter (793972)
FIXED
Unity plugin doesn't display in HiDPI mode (829284)
All languages here http://www.mozilla.org/en-US/firefox/all/ or can update via FF browser.
Release Notes link http://www.mozilla.org/en-US/firefox/20.0/releasenotes/