I've been doing a lot with ASP.NET AJAX for almost 2 years now, including my Web.Maps.VE product. So, I've decided to spread some of my knowledge in this area by writing up some articles on things that I've learned and figured out. The ScriptControl is basically the first building block you want to use to start building out a WebControl (server control) that will have some kind of rich AJAX functionality in the browser. You may have heard of ASP.NET AJAX Control Extenders, especially if you're familiar with the AJAX Control Toolkit, so why would we use ScriptControl instead of creating an ExtenderControl in order to give a control some rich AJAX functionality within the browser? Well, you want to create an ExtenderControl to extend or enhance an existing control with some rich AJAX functionality, and you want to inherit from the ScriptControl class when you are creating a full control that will have some rich AJAX functionality.