I'm making my sample Visio Ribbon available today. The source is attached.

Some notes:

• This was a throw-away prototype. (in other words, it isn't very clean or well-designed)
• The code is not commented, not extensively tested.
• Not all features are implemented
• Use at your own risk

When the add-in is loaded, you will see a new toolbar. Select Doc and select a document size that you like.

A new document will be created. Now click Ribbon to show the ribbon.

And then you will be able to see the simulated ribbon.