ASP.NET composite custom controls provide the functionality of combining groups of existing controls, which promotes reuse. For deployment, you can move the DLL associated with a composite control anywhere, adding it to the tool palette just like any other control. To make a control easier to use, you should add properties, enabling developers to modify the design-time state of the control with C#Builder. Another capability you should add to controls is including public events, when appropriate. By adding properties and events, you can extend the value of controls by making them easier to work with in IDEs.