Quality is delighting customers
Give a try with Telerik webui test studio, it support's silverlight and telerik controls.
You can even get a free 30 days trail version, i worked on the same tool around one year.. support team and compatibility is gud..
QTP latest version supports Silverlight applications, you need to get separate Add in for Silverlight.
Hope you are not specific about open source ;)
current latest version of QTP is 12. Please confirm whether QTP12 is supporting silverlight windowbased applications or not
I am using QTP 11 and Silverlight 5 it is working fine you have install Silvelight in your local system .
TestComplete by SmartBear supports automated testing for Silverlight applications.
What exactly are you trying to do?