User Interfaces in VB .NET: Windows Forms and Custom Controls

Extender Providers are a useful idea and an easy way to add additional properties to existing controls. Other uses for extenders include adding layout management such as Flow, Grid, or GridBag layout to a Form at design-time. Of course, you'll also have to implement the layout logic, but using extenders allows for assigning various layouts to different elements of a form. The uses for extenders are limited only by your imagination and necessity.