This small webapp is an experimental viewer / editor for log files collected by its companion addon-sdk library: rdp-logging
Using rdp-logging (or another equivalent tool) we can collect Mozilla Remote Debugger Procotol exchanged messages into a simple json format file, and then (using a viewer like this) we can render it into a readable sequence diagram (a very simple UML Sequence Diagram) and optionally tweak it using the embedded editor (e.g. to design a change in the protocol).
This prototype is based on the following opensource projects: