Alvas.ShapeForms (Windows.Forms) is a collection of 100% native .NET framework managed controls written in C#.
Collection allows developers to create high quality professional applications with nonrectangular forms.
How to use

Place some ShapeRegions or/and BitmapRegions on the form.
Place RegionManager on the form and set your Form property to the current form.
Set Form property of the RegionManager to true/false.
Enjoy.
Package contains:
RegionBase which implements the basic functionality common to region controls.
ShapeRegion which represents a shaped region.
BitmapRegion which creates region from bitmap.
RegionManager component which manages the interaction of controls, derived from RegionBase (ShapeRegion and BitmapRegion).
See demo application for more info...