Silverlight Inspector

Silverlight Inspector is a utility for inspecting Silverlight XAP files. Developers and designers can use it to view the visual tree of an application and/or control and view assemblies within a XAP.

Silverlight Inspector works by downloading and modifying the XAP file you specify. The application downloads the given XAP, modifies its AppManifest.xaml, inserts AGHikariInjector.dll, and launches Sllauncher.exe with the new XAP file.
AGHikariLauncher contains a basic UI for creating new instances of FrameworkElement-derived objects in each assembly, and a visual tree inspector for inspecting each instance.