Throughout the software development process a set of models are used to represent different views of the system. Those models are generally enriched by additional information and transformed from more abstract into more concrete ones by applying a set of model-to-model transformation. The Model Driven Engineering (MDE) therefore considers models as being the most important element for software development, maintenance and evolution. One of the relevant standard of MDE the Model Driven Architecture (MDA) which is an instance of MDE developed by OMG since 2000. Moreover, the MDA allows also the code generation from platform specific models by the mean of generators which automatically transforms models into source code for the chosen platform. this book presents an example of JEE code generator using the principals of the MDA.