AvalonDock adheres to an MVVM design.

The Model is represented by the classes contained in the Xceed.Wpf.AvalonDock.Layout namespace. The classes in this namespace are the layout elements in a layout model (for example LayoutAnchorable/LayoutDocument, LayoutAnchorablePane/LayoutDocumentPane, LayoutAnchorablePaneGroup/LayoutDocumentPaneGroup, etc.) that are used directly in XAML within a DockingManager to describe how the layout is composed.

The View is represented by the classes contained in the Xceed.Wpf.AvalonDock.Controls namespace; these classes are a set of stylizable controls that show the user controls. The names of the view controls typically end with "Control" (for example, LayoutAnchorableControl is the view control, whereas LayoutAnchorable is the model element).

The DockingManager uses various classes (such as the LayoutItem and its derived classes) to perform the role of the ViewModel, preparing the model to be consumed by the view.

There is one and only one logical tree, which has the DockingManager as its root. Even if a control is placed in a different window (i.e., autohidden windows or floating windows), it always belong to the same logical tree below the DockingManager.

System.Object
   System.Windows.Threading.DispatcherObject
      System.Windows.DependencyObject
         System.Windows.Media.Visual
            System.Windows.UIElement
               System.Windows.FrameworkElement
                  System.Windows.Controls.Control
                     Xceed.Wpf.AvalonDock.Controls.LayoutAnchorableTabItem

Target Platforms: Windows 11, Windows 10, Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

Reference

LayoutAnchorableTabItem Members
Xceed.Wpf.AvalonDock.Controls Namespace