Firefox Developer Edition Notes

Version 38.0a2, first offered to Firefox Developer Edition users on February 27, 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.

For more information about Developer Edition please see this MDN article and also this hacks.mozilla.org post.

What’s New

  • New

    New tab-based Preferences

  • New

    64bit Windows builds (download here)

  • New

    Hello: active tab and window sharing when in a conversation

  • New

    Reading List

  • New

    Mac OS X: Implemented a subset of the Media Source Extensions (MSE) API to allow native HTML5 playback on YouTube

  • Changed

    autocomplete=off is no longer supported for username/password fields

  • Changed

    URL parser avoids doing percent encoding when setting the Fragment part of the URL, and percent decoding when getting the Fragment in line with the URL spec

  • Changed

    RegExp.prototype.source now returns "(?:)" instead of the empty string for empty regular expressions

  • Changed

    Page load times improved by speculative connection warmup

  • HTML5

    Implemented srcset attribute and <picture> element for responsive images

  • HTML5

    Implemented DOM3 Events KeyboardEvent.code

  • HTML5

    BroadcastChannel API implemented (more at hacks.mozilla.org)

  • HTML5

    Implemented Encrypted Media Extensions (EME) API to allow encrypted video playback

  • Developer

    Optimized-out variables are now visible in Debugger UI

  • Developer

    XMLHttpRequest logs in the web console are now visually labelled and can be filtered separately from regular network requests

  • Developer

    WebRTC now has multistream and renegotiation support

  • Developer

    copy command added to console