A software industry producing high-quality components that can be reused in many ways is an—unfulfilled—dream as old as the field of “software engineering” itself. In this paper we present an evolutionary approach to software development based on the following premises: software systems are unavoidably heterogeneous and distributed; development and implementation techniques may be different for various parts of a system; the parts may be in different phases of their life-cycle; the parts—implemented as components in different languages—should be coordinated and exchange information in a standardized fashion; reengineering and system renovation form an integral part of software development.