In a two monitors scenario the ApplicationMenu appears on the left monitor when the RibbonView with negative left margin is hosted in a RibbonWindow which is maximized on the right monitor.

EDIT:
We are closing this issue as the described behavior as expected. When logged first, the negative left margin of RibbonView was not taken into account.
When popup opens and its parent starts on the left monitor, popup calculates that it cannot fit entirely and changes its direction of opening. This expected by the WPF Framework.
When you give negative left margin of the RibbonView, its application button might also goes with 1-2 (or more) pixels on the left monitor. Then popup (the application menu opens in a popup) has no space and changes its opening direction to left.
This is expected and the only reasonable solution would be changing the negative left margin to positive or 0.

The BackstageItems are not rendered as expected when the RadRibbonView is hosted in apanel with flow direction set to right to left.

TreeView or DataGrid, or COmbobox is placed in a dropcontent of a RibbonDropDownButton. Item is selected programmatically before the dropdown is loaded. This leads to null reference exception.

Currently, when the users hover around the window's border, the resizing border is 1 pixel wide. Create the border wider (higher at top and bottom borders).
 
Workaround: Apply right margin to the content inside the window.

If you open the dropdown of the RadRibbonComboBox using the keytips support and then navigate to an item, and select it using the arrow keys, the selection is wrong. It selects the next item instead of the one highlighted by the keyboard navigation. 

In XP and Windows10, the window goes behind the windows task bar when it is maximized.
The problem manifests itself if we set explicitly the "WindowStyle" property of the RadRibbonWindow.
With its "default" value, the problem do not exists.
It is also reproduced when AllowTransparency = True (it requires WindowStyle = None), which is needed to set a drop shadow effect.

When the window is resized, the Title should transform to Shorter Text + "...." like in MS Officce (Word, Excell, etc.)

The title of the RadRibbonWindow can't be trimmed when resizing the window. Even the window's buttons are overlapped

Add thin border in the RadRibbonWindow between the Tittle and RibbonView.

We want the look of the window to be identical to how a non-implicit RadRibbonWindow would look (i.e., without the Themes directory with the style XAML files). Alternatively, if the title bar is taller and the borders are as thick as a normal window (e.g. Notepad), that is acceptable too.

ApplicationName is  off center when TabStripAdditionalContent contains an element with long text/content

RibbonWindow icon appears clipped when the DPI  is set larger than 100%. Also, the icon separator is offset.

Available in LIB version: 2016.1.21

Currently, you can navigate through the elements of the ribbon only via the keytips or the arrow keys. Add support for the Tab key as well.

In other words when you enter the keyboard navigation mode, the Tab key should work along with the arrow keys. See Word's ribbon for a reference.

 

Expose a property to control the visibility of the backstage back button.

Currently, a ScreenTip is opened 500 milliseconds after you hover the associated item. This is a hardcoded value that cannot be changed. Add a property to change this. For example another attached property in the ScreenTip class.

For example: ScreenTip.InitialShowDelay="1000"

Add an way to include the Microsoft standard "Press F1 for help" to screentips in the ribbon, including the behavior to perform an action when the F1 key is pressed.

UPDATE: The RibbonView exposes a HelpCommand property which basically sets the Help button command. Additionally the Help button has a predefined ScreenTip which content is controlled by the “RibbonViewHelp” resource key. You can easily change the value returned by the ResourceManager for that resource key to change the default ScreenTip information.

As for performing a custom action on F1, this is considered application logic which can easily be implemented through InputBindings (http://msdn.microsoft.com/en-us/library/system.windows.uielement.inputbindings%28v=vs.110%29.aspx).

ActivatePreview event does not fire when the  gallery is databound

Available in Q1 2015 Release.

Close command needed when using the close button

The command could be intersected as follow: 
 static MainWindow()
{
      RadRibbonWindow.IsWindowsThemeEnabled = false;
       CommandManager.RegisterClassCommandBinding(typeof(MainWindow), new CommandBinding(Telerik.Windows.Controls.RibbonView.Shell.SystemCommands.CloseWindowCommand, CloseWindowExecuted, canExecute));
}

Please note that this command is available only if RadRibbonWindow.IsWindowsThemeEnabled is set to "false".

Available in R1 2017 Release

Expose a property to control the Visibility of the RibbonWindow icon separator

Declined: The Icon separator could removed once the Windows is loaded, like follows: void MainWindow_Loaded(object sender, RoutedEventArgs e) { var iconPanel = this.ChildrenOfType<FrameworkElement>().Where(x => x.Name == "IconPanel").FirstOrDefault() as StackPanel; if (iconPanel != null) { var border = iconPanel.ChildrenOfType<Border>().FirstOrDefault(); if (border != null) { border.Visibility = System.Windows.Visibility.Collapsed; } } }