It seems that Mcneel started testing a new user interface with the cool tab function. It allows you to easily intergrate your most used tools into Tabs.
rhino classic user interface
rhino new ui
If you want to switch to new ui, just type the command: testfancytoolbars and open your default toolbar layout(*.tb) or the file (*.rui) of Automatic Generation. The program will convert the toolbars you tick into tabs Automatic, You can also drag other toolbars whatever you want to insert an existing tab.
You can even change the tab/background/… colors to match your taste.
Do you have some ideas about this new user interface? For me, it looks ok.