Aurora is more than a drawing or painting program. Aurora works with the Windows Presentation Foundation (WPF) object model and the Visual Tree. Aurora allows you to visually create and edit various levels in the WPF document. In addition to creating user interfaces and drawings, Aurora allows you to apply attached dependency properties to visual objects; you can also define custom content for content controls. Using Aurora you can use or create libraries of objects and reuse them in your applications. The Aurora authoring engine is built as a WPF DockPanel that can be dropped into a WPF application or can be embedded in a WinForms application providing instant XAML/WPF authoring capabilities. The DesignerPanel is the main class for the authoring engine. It is derived from a DockPanel and implements the AuroraDesigner interface which is the main interface for the Aurora Object Model. The DesigerPanel lives in the AuroraDesigner.dll. The Aurora Designer has a plug-in architecture that allows third-parties to create their own plug-ins. The plug-in has complete access to the toolbars, tabs, Property Panel and Solution Explorer in Aurora through the Aurora Object Model. The Plug-in can create custom toolbars, create custom WPF based controls and even launch custom editors. Using the various events and interfaces in the Aurora Object Model and the flexibility inherent to WPF, the behavior of the Aurora Designer can be customized to the application being developed by the host program.