Hi there I'd like to be able to understand how to develop a Flex application such that I could provide implementation classes at runtime. In the Java world I'd specify interfaces in an JAR (e.g. myapp-api.jar), the implementation in a separate JAR (e.g. myapp-impl.jar) and package these along with other resources in the application WAR (e.g. myapp.war). Within the code of the application I would instantiate the implementation classes dynamically. Is this approach possible in Flex? I'm aware that I can instantiate classes dynamically so that's a good start. I'm a bit confused by modules, RSLs and SWCs though. I was hoping to create a SWF application that had references to an interfaces SWC and an implementation SWC. The idea is that if I need to tweak the application for a specific customer then I could create a new implementation SWC and not have to modify the SWF or interface SWC. Any ideas?