Firefox Developer Edition
Release Notes

Smoother scrolling for Web content

HTTP sites containing login forms will be marked insecure

Improved security of the JavaScript Just In Time (JIT) Compiler

GTK3 integration (GNU/Linux only)

Added support for WebKitCSSMatrix to improve mobile Web compatibility

WebRTC fixes to improve performance and stability

Display dominator trees in Memory tool

Launch responsive mode from the Style Editor @media sidebar

Allocation and garbage collection pause profiling in the performance panel