KitKat official version.
(Here the previous Community edition: 2.3.02.2.0, 2.1.0)

From Forum Post:

Changelog (2.4.0) ( Current release )
– USB fixes ( X5 series )
– Sleep working (X5 series)
– Camera fixes
– Full redesign of the media framework ( more video apps should work now by default HLS 0 ! )
– fixed permission issues.
– disabled multi user for now, till we find a remote friendly lock-screen.
– Rendering a new layer for video.
– X5 series have full 1080p now ( screen scale works )
– updated pre-installed apps
– New OTA methods
– After fw update also preinstalled updates will reinstall.
– new bigger mouse pointer.
– Google play music added to pre-installed apps.
– Updated the pre-installed apps.
– Google play music, Hulu Plus, Youtube live are working !
– No missing bitmaps any more during recovery.
– and lots of things you wont even notice