The Silverlight Business Application is fully localizable and Customizable. To understand this feature create Silverlight Business Application, I gave application name "SampleBusinessApplication".
This will add two projects in solution, "SampleBusinessApplication" and "SampleBusinessApplication.Web". Now for example, you want to change the name of application which is displayed at top left corner of Silverlight business application, go to SampleBusinessApplication project and open ApplicationStrings.resx (from Assets\ Resources folder) in resource designer. Modify "ApplicationName" resource to "My Demo Application".
When you run the sample application you can see the application name is changed to "My Demo Application".
This is one of the many cool features available in Silverlight. You can make use of resources to target many other locals as per your project requirement.