When I started understanding ECom architecture of Symbian, I tried to map it with some design pattern from the GoF book. This way I found out that the Strategy Pattern described as one of the Behavioral Patterns is the closest match. Let me share my understanding with you.

Sony Ericsson Developer portal has posted the source code of a small application that shows how to list information about all MMF controller plugins from the ECOM registry on Sony Ericsson's UIQ 3-based phones. A controller is a MMF plugin that supports playing and recording one or several multimedia formats. Most MMF audio and video interfaces use the multimedia controller framework to provide functionality to read and write audio and video data.

One of the most important design in Symbian is the well-known server/client framework. As the server and client are in different process spaces, hacking the server is generally difficult to achieve by means of normal application. This tutorial reveals a new way to hack the server heap and make a patch as you want.