WPF Docking contains a set of common components under DevZest.Windows namespace. These components are used for styling and templating of WPF Docking extensively. You can use these component in your own application, commercial or non-commercial, free of charge (a Free Feature license may required).

You can find samples for these common components under Common folder of installed Samples zipped folder, in both VB.Net and C#:

AdornerManagerProvides attached properties to get or set a UIElement or DataTemplate as adorner of FrameworkElement. You can use this class to declare adorner of FrameworkElement in XAML.
DropDownButtonRepresents a button that drops down a context menu.
ReverseCollectionViewSourceRepresents the Extensible Application Markup Language (XAML) proxy of the CollectionView class, in a reversed order.
SplitContainerRepresents a control consisting of two resizable UIElement objects (Free Feature License required).
WindowPanel and WindowControlRepresents a collection of movable and resizable windows.