The Renaissance method was developed to support the reengineering of legacy software systems-that is, the transformation of valuable software assets which are difficult to maintain into new systems which can evolve both in the short and long term.The method is structured into two main phases. The first one, or "what to do," aims to assess the organisation and the legacy system and identify both the need and urgency of reengineering and the best candidate strategy to adopt for renewing the system: continue with the current maintenance approach; re-engineer the system from user-interface, structure, architecture, and/or design point of views; replace the existing system with a new developed one. The second phase, or "how to do," supports the implementation of the planned transformation, and drives the overall process of migrating the legacy system to its immortal dimension.