Firefox Beta and Developer Edition
Release Notes

New HTTP cache provides improved performance including crash recovery

Integration of generational garbage collection

Public key pinning support enabled

View historical use information for logins stored in password manager

Display the number of found items in the find toolbar

Support for connecting to HTTP proxy over HTTPS

Mac OS X: cmd-L does not open a new window when no window is available

Text Rendering Issues on Windows 7 with Platform Update KB2670838 (MSIE 10 Prerequisite) or on Windows 8.1

Removed and turned off trust bit for some 1024-bit root certificates

Performance improvements to Password Manager and Add-on Manager

HiDPI support in Developer Tools UI

Inspector button moved to the top left

Hidden nodes displayed differently in the markup-view

New Web Audio Editor

Code completion and inline documentation added to Scratchpad

drawFocusIfNeeded enabled by default

ECMAScript 6 built-in method Array#copyWithin implemented

CSS position:sticky enabled by default

mix-blend-mode enabled by default

New Array built-in: Array.from()

navigator.languages property and languagechange event implemented

Vibration API updated to latest W3C spec

CSS box-decoration-break replaces -moz-background-inline-policy

Repeating background image causes weird text layout issue with HWA off (1011166)