Use the following link to download the first beta of the ribbon control.
The download is just a zip file that contains the toolkit and ribbon assemblies and two executables that are simple examples showing the ribbon control in action. Unzip the file to a new directory and then run the two samples to play around with it. You can add the ribbon assembly to your toolbox and so create a krypton application that uses the ribbon.
Note that this beta version is not feature completed. It does not have any keyboard support and so it does not have KeyTips or the ability to navigate around its contents using the keyboard. This is the next feature I will be working on. It also does not have any explicitly created design time support.
You can update the ribbon at design time but you need to use a combination of the Document Outline tool window and the Properties tool window. Start by looking at the RibbonTabs collection property. Please report any bugs to the ribbon forum and any other feedback, negative as well as positive!