继昨日Firefox 19正式版发布之后，Mozilla今天又发布了Firefox 20.0 beta1版本，支持了全新的下载窗口了，
下载地址：
http://download.cdn.mozilla.net/pub/mozilla.org/firefox/releases/20.0b1/win32/zh-CN/
NEW
Per-tab private browsing
NEW
Gingerbread and Honeycomb support for H.264/AAC/MP3 hardware decoders
CHANGED
System requirements have been lowered to 384MB of RAM and QVGA displays
DEVELOPER
CSS3 Flexbox implemented and enabled by default
DEVELOPER
Continued implementation of draft ECMAScript 6 - clear() and Math.imul
HTML5
<canvas> now supports blend modes
HTML5
Various <audio> and <video> improvements
HTML5
getUserMedia implemented for web access to the user's camera and microphone (with user permission)