Uses WixPrerequisiteBootstrapperApplication as a secondary Bootstrapper Application for a Bundle, to bootstrap the prerequisites needed for a primary bootstrapper application. Extensibility point in the WiX XML Schema. Schema extensions can register additional elements at this point in the schema. Source file of the logo graphic. Source file of the theme XML. Source file of the theme localization .wxl file. The built-in theme to use. The default is "standard". Extensibility point in the WiX XML Schema. Schema extensions can register additional attributes at this point in the schema.