Firefox Developer Edition
Release Notes

Added protection against unwanted software downloads

New style for add-on manager based on the in-content preferences style

Improved scrolling, graphics, and video playback performance with off main thread compositing (GNU/Linux only)

Process separation enabled for opt-in testing

Graphic blocklist mechanism improved: Firefox version ranges can be specified, limiting the number of devices blocked

Kannada text does not display properly in built-in pdf viewer

NPAPI Plug-in performance improved via asynchronous initialization

Smoother animation and scrolling with hardware vsync (Windows only)

JPEG images use less memory when scaled and can be painted faster

Support for running animations of 'transform' and 'opacity' on the compositor thread

Sub-resources can no longer request HTTP authentication, thus protecting users from inadvertently disclosing login data

Improved Performance tools in the developer tools: Waterfall view, Call Tree view and a Flame Chart view

New rules view tooltip in the Inspector to tweak CSS Filter values

New page ruler highlighting tool that displays lightweight horizontal and vertical rules on a page

Console API messages from SharedWorker and ServiceWorker are now displayed in web console

Inspector now searches across all content frames in a page

Removed support for binary XPCOM components in extensions, use addon SDK "system/child_process" pipe mechanism for native binaries instead

IndexedDB transactions are now non-durable by default

Implemented AudioBufferSourceNode.detune to modulate playback rate in cents, a logarithmic unit of measure used for
musical intervals

If Firefox is restarted from an add-on install notification, on-going private browsing downloads might be canceled without warning (1185294)