Silverlight client-side database

Many times on Silverlight you need to store data on client machine. Some examples would be: undo/redo functionality for your application, games user data, demos/presentations to clients of your application, store data locally while user navigate on your application and only at the end you want to commit changes on server side storage and examples can continue. Also if you use Silverlight Out-Of-Browser application you almost need mandatory a client – side database....