Firefox Developer Edition Notes

Version 42.0a2, first offered to Firefox Developer Edition users on August 14, 2015

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

What’s New

  • New

    Improved private browsing windows block some web page elements that could track your web behavior across sites

  • New

    GTK3 integration (GNU/Linux only)

  • New

    Hardware acceleration for 2D canvas content (Mac OS X only)

  • New

    Indicator added to tabs that play audio with one-click muting (Adobe Flash supported since version 19)

  • New

    Process separation enabled by default in Developer Edition

  • New

    Intuitive Control Center contains restyled site security, site identity and private browsing

  • New

    Improved performance on interactive websites that trigger a lot of restyles

  • New

    Add-on signing enforcement

  • HTML5

    Implemented ES6 Reflect

  • HTML5

    Implemented new standard Push API

  • HTML5

    Support ImageBitmap and createImageBitmap()

  • Developer

    Asynchronous call stacks now allow web developers to follow the code flow through setTimeout, DOM event handlers, and Promise handlers.

  • Developer

    Remote website debugging over WiFi (no USB cable or ADB needed)

  • Developer

    Configurable Firefox OS Simulator in WebIDE, to simulate reference devices like phones, tablets, even TVs

  • Developer

    CSS filter presets in the Inspector