SplitWindows is a plugin which is similar to the Editor interface. Like the Editor, it is also assembled by multiple slates. Using this plugin, you can better understand how the Editor interface works, and even design the window style you want, including the viewport.
Overview Video
SplitWindow builds an interface similar to Editor, including ToolBar, Viewport, Placement, Details.To be more precise, it is a demo project to help developers understand and use Slate.