ColdFusion 8 added the cfinterface tag, which enables CF developers to use interfaces in their applications. Interfaces specify one or more functions that a ColdFusion component must implement. Coming from being a Java programmer to primarily doing ColdFusion web application development, I missed using interfaces. To help me learn how to use the new cfinterface tag, I implemented the SimUDuck application from chapter 1 of Head First Design Patterns. You can download the code (see the references below) for the application. I'll briefly walk through how cfinterface works.