This volume gives a coherent presentation of the outcome of the project PROSPECTRA (PROgram development by SPECification and TRAnsformation) that aims to provide a rigorous methodology for developing correct software and a comprehensive support system. The results are substantial: a theoretically well-founded methodology covering the whole development cycle, a very high- level specification and transformation language family allowing meta-program development and formalization of the development process itself, and a prototype development system supporting structure editing, incremental static- semantic checking, interactive context-sensitivetransformation and verification, development of transformation (meta-) programs, version management, and so on, with an initial libraryof specifications and a sizeable collection of implemented transformations. The