Perusing the the Composite Application Wiki I discovered a technology IBM calls jWidgets. Basically they are for Composite Application Java component development what iWidgets are to websites that is a widget framework for easily and more quickly doing stuff. Developing Java components for composite applications is a little hard as you have to manage wires etc. yourself. A framework would make that a lot easier and that's exactly what jWidgets are.
Having the technology available to Lotus Notes (and not just Lotus Expeditor) would be really cool. From an IBM'er I however learned that they haven't been formally tested in Notes, but the technical capability is there. They have only been tested formally in Lotus Expeditor 6.2.2.