Legacy information systems can be a serious headache for companies because, on the one hand, these systems cannot be thrown away since they store a lot of valuable business knowledge over time, and on the other hand, they cannot be maintained easily at an acceptable cost. For many years, reengineering has been a solution to this problem because it facilitates the reuse of the software artifacts and knowledge embedded in the system. However, reengineering often fails due to the fact that it carries out non-standardized and ad hoc processes. Currently, software modernization, and particularly ADM (Architecture-Driven Modernization), standardized by the OMG, is proving to be an important solution to that problem, since ADM advocates carrying out reengineering processes taking into account the principles and standards of model-driven development. This chapter provides an overview of ADM and shows how it allows legacy information systems to evolve, making them more agile, preserving the embedded business knowledge, and reducing maintenance costs. Also, this chapter presents the software archeology process using ADM and some ADM success stories.