Progress Telerik UI for WinForms
Unlike RadForm, RadShapedForm actually descends from a standard Windows Form. It comes with a RadTitleBar so the user can move, close, minimize and maximize the form. Both the RadTitleBar and the ShapedForm by default each have their Shape property set to RoundRectShape. You can also use one of the predefined shapes, or you can create your own custom shape using the Shape Editor tool.