Is the CustomUI ribbon customization scheme implemented in Office 2011? From the package file, it looks like the Ribbons are implemented as nib files instead, which (inconveniently) require a MS custom IB plugin..

It seems odd that MS would create an entire XML-based dynamic UI system (similar to Netscape's XUL-based system?), but not implement it in the MacOS codebase. Although it may be that the most work went into recoding the VB engine for Intel for Office 2011 - does this mean that the Mac will get OpenXML customizable interfaces in Office 2013?