FCG is an AIR application which primary goal is to automatically provide the base code for your RemoteObject based Flex applications. Basically, it means that it reads some code from the server side, and creates a bunch of MXML and AS files to boost your productivity. Its goal is not to create a ready-to-use application, but to provide the tools you need to do so as quickly as possible.
The following example shows how you can use the decodeXML() method in the SimpleXMLDecoder class to convert an XMLDocument object into an ActionScript Object object.
Class annotations, also known as metadata in Flex, are extremely valuable as they allow developers to provide additional information about classes, properties and methods which may not be appropriate to convey through implementation details such as Marker interfaces or some other means