During their lifetime software systems undergo repeated maintenance and evolution activities to correct faults, or to meet the customers’ or market’s needs. In particular, recently a large part of the maintenance effort has been devoted to the migration of traditional applications to integrate them into web and service-oriented architectures or to make them accessible from wireless devices. The effort devoted to maintenance and migration activities is a large part of the total life-cycle effort, and it could be greatly reduced by adopting proper tools to support reverse engineering and reengineering activities. This book provides an overview and the main results achieved in the project METAMORPHOS, a two year project funded by MIUR (Ministero dell’Istruzione, dell’Università e della Ricerca) under program PRIN (Progetti di ricerca di Rilevante Interesse Nazionale) 2006. The project started on February 2007 and has been carried out by four research groups of the University of Salerno (project coordinator), the University of Sannio, the University of Bari, and the Polytechnic of Turin, respectively. The objective of the project was to facilitate industry in the selection and the adoption of reverse engineering and reengineering techniques and tools that support migration towards the Web and wireless infrastructures. To pursue this objective, the project aimed at empirically evaluating techniques and tools that can potentially fulfil the industry needs.