Firefox Developer Edition
Release Notes

SVG images can be used as favicons

Memory overhead of AdBlock Plus has been greatly reduced

WebRTC now requires perfect forward secrecy

Updates to image decoding process

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

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

Network requests can be exported in HAR format

View HTML source in a tab

Quickly add new CSS rule with New Rule button in the Inspector

Screenshot a node or element from markup view with the Screenshot Node context menu item

Copy element CSS rule declarations with the Copy Rule Declaration context menu item in the Inspector

MessageChannel and MessagePort API enabled by default

Added support for the transform-origin property on SVG elements

Copy/Cut Web content from JavaScript to the OS clipboard with document.execCommand("cut"/"copy")

Implemented Cache API for querying named caches that are accessible Window, Worker, and ServiceWorker

CSS Font Loading API enabled by default

Navigator.onLine now varies with actual internet connectivity (Windows and Mac OS X only)