Always wanted to have smaller XAP files and take control of external assemblies, that are not part of core runtime? Using Silverlight toolkit and want to cache this assemblies on client machines to keep the resulting XAP smaller? Well, if so new feature in Silverlight 3 Beta will help you. To enable assembly caching, in Silverlight project properties check “Reduce XAP size” checkbox: The effect are following: In standard non-checked compilation the XAP file has all the external assemblies being referenced...