Mozilla Firefox today will be Mozilla Firefox 51 Beta 7 sent to the official FTP server, the new Beta version reduces the CPU footprint and GPU rendering performance, an increase of WebGL support in the address bar to add a scaling instruction, while the FLAC lossless music format Playback provides support. For Windows 10 touch devices, version 51 of the E10S multi-process feature has begun to operate.
For more information about Developer Edition please see thisMDN article.
Added support for WebGL 2
Remove Belarusian (be) locale
Support saving passwords for forms without 'submit' events
Improved video performance for users without GPU acceleration:
Less CPU Usage
Better full screen experience
Zoom indicator is shown in the URL bar if the zoom level is not at default level
View passwords from the prompt before saving them
Use Skia for content rendering (Linux)
Process separation(E10s) now supported on Windows 10 touch screen devices and systems with accessibility tools installed