SandDock for Silverlight
SandDock is software that enables dockable floating windows.
SandDock is award-winning window management software that enables dockable floating windows, tabbed documents and other advanced window management functionality in applications that use it.
By plugging SandDock into your project you can forget about the intricacies of window layout; instead, provide your windows to SandDock and let it present them with all the tools your users need for full customization of the working area. Tool windows become dockable, sticking to the sides of your window in hierarchies chosen visually by the user; or they can be floated above your main window, or even collapsed to the side. Documents are presented in a tabbed fashion, with split views for easy comparison between content.