This article is for Silverlight 2 beta 1 There is a common misconception that User Controls in Silverlight must be placed in the assembly from which they are referenced. However, this is not true, you can have user controls in an assembly and use them from another assembly. This is not a direct process, however, so let's see how to proceed: Preparing the control Create a new Silverlight 2 application in Visual Studio. In this example, we'll name this application "UserControlsPacking". For this first application, you can choose to generate a test web application, or to use a basic HTML test page. In the same solution, create another Silverlight application. Let's name it "UserControlsPacking.Controls". Choose the "Generate a HTML test page" option, to avoid creating unnecessary test projects. In the moment, Silverlight 2 beta 1 has only 2 project templates available: "Silverlight Application" and "Silverlight Class Library". Ideally, we would need a "Silverlight User Control Library", just Read More...