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Firefox Notes (First offered to release channel users on April 11, 2013)

Check out "What’s New" and "Known Issues" for this version of Firefox below. As always, you’re encouraged to tell us what you think, or file a bug in Bugzilla. We'd also like extend a special thank you to all of the new Mozillians who contributed to Firefox 20!

If interested, please see the complete list of changes in this release.

What’s New

  • FIXED
    20.0.1 - Windows-only update to handle issues around handling UNC paths (see bug 846848)
  • 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
    20.0.1: Security fixes can be found here
  • FIXED
    Details button on Crash Reporter (793972)
  • FIXED
    Unity plugin doesn't display in HiDPI mode (829284)

Known Issues

  • Unresolved
    If you try to start Firefox using a locked profile, it will crash (see 573369)
  • Unresolved
    Some function keys may not work when pressed (see 833719)
    Unresolved on v19 Resolved in v21
  • Unresolved
    Browsing and Download history clearing needs unification to avoid confusion on clearing download history (see 847627)
    Unresolved on v20 Resolved in v21
  • Unresolved
    Download statusbar add-on continues downloading files from Normal Browsing, when switching to Private Browsing (see 853463)