It seems that the OpenOffice development team has decided on the prototype of the new interface. Their solution is an inverted ribbon from Microsoft.
It looks awful, in my opinion, but note that this is a prototype and the appearance is presented only for the purpose of working out the solution itself. However, it seems that the idea of the ribbon as a group of themed tabs will still appear in OpenOffice three years later (or more, who knows when the release?) Will appear in Microsoft Office.