The Telerik editor has a nice style builder/editor built in. It would be terrific if your ASP.NET tool set included a custom control that was a standalone style builder / editor. Our product includes web design tools and we need to give our customers the ability to customize the many styles used in the system. Ideally, it would be programmable, with many properties and methods so that we can customize it (for example, to remove options we don't want them modifying or to hide individual tabs that don't apply to the current style.) Also, it should support as much of CSS3 as possible (for example, curved corners on borders, that the current style sheet editor does not provide.)