Hi Michael.

What's the compatibility degree of the upcoming V4 with the current latest V3 ?

More in depth :

1) Scripts.
The new API core (if there is a new one) will be backward compatible with the current API ?
All the Scripts written for V3 will continue to work properly on V4 ?

2) .3dm file format
Moi V4 will use by default the Rhino 5 format instead of Rhino 4 ?

3) Html files.
The new V4 will accept all custom html files used to customize V3's UI ?

4) Shortcuts
Can I use with V4 all the hotkey setup that I currently use for V3 ?

Thanks a lot and have a nice day.