Microsoft just made available the July release of the Microsoft Ribbon for WPF in MSDN. This is the RTW release of the Ribbon control, compatible with WPF 3.5sp1 and WPF 4.

This release is a managed implementation of the Ribbon for WPF. The Ribbon is a command bar that organizes the features of an application into a series of tabs at the top of the application window, is designed to help you quickly find the commands that you need to complete a task. The Ribbon user interface (UI) increases discoverability of features and functions, enables quicker learning of the application, and helps users feel more in control of their experience with the application. The Ribbon replaces the traditional menu bar and toolbars.

Besides the Ribbon download itself, there’s also a sample installer available. These samples include:

• RibbonWindow Wordpad Sample This sample illustrates a Ribbon control hosted within a RibbonWindow that emulates the Wordpad appearance.
• RibbonWindow MVVM Sample This sample illustrates a Ribbon control hosted within a RibbonWindow that is completely populated from a view-model collection.
• RibbonBrowser Wordpad sample This sample illustrates a Ribbon control hosted within a browser window that emulates the Wordpad appearance.
• RibbonBrowser MVVM sample This sample illustrates a Ribbon control hosted within a browser window that is completely populated from a view model collection.

You can download WPF Ribbon Control for WPF here.