This blog post is part of my research on whether the RadControls for ASP.NET Ajax support Microsoft Expression Web? The answer is simple – yes, they do.
If you only follow the instructions on how to use custom controls in Expression Web, you will see the result yourself. The main point here is having the Telerik.Web.UI assembly in the GAC and register it with its fully qualified name on the page.
Here are some screenshots:
Design-time:
Run-time: