Office 2007 clients (Word, Excel, PowerPoint, Access and partially also Outlook) have a new user experience. I think most of you already got that. The new ribbon experience is also very extensible and you can do this at the document/template level by dropping the extension in the package or by working at the application-level and creating a VSTO add-in. For the former approach (the document-level one) there is a small but very useful tool available from the Open XML Developer community site (http://openxmldevelopers.org) called the Custom UI Editor. Very nice little tool to demonstrate the power of the ribbon extensibility.
Check this out:
1. Open the tool
2. Open an existing Word 2007 document
3. Start with a sample ribbon XML snippet. If you create your own there is the option to validate your XML.
4. Save and close the tool
5. And there you go... open the Word document and find the custom ribbon
