I found several controlsets for that nice looking ribbons (DotNetBar, DivElements, ...), but all require a license for at least 100 USD. Is there a free controlset that looks quite as nice as the commericial ones?
You can download the Microsoft WPF Ribbon Control through the Office Developer UI Licence.
It was meant to be released last week.
http://windowsclient.net/wpf/wpf35/wpf-35sp1-ribbon-walkthrough.aspx
I'll see if i can dig out a download link.
Edit:
Think this is what your looking for Office Fluent User Interface Developer Portal