New and innovative techniques for software development are needed to improve productivity and enhance reliability. Object-Oriented development offers the greatest potential for achieving these goals. However, Object-Oriented techniques have not been widely applied across all stages of the development lifecycle and Object-Oriented CASE tools are not widely available. A simple methodology, based upon Object- Oriented techniques and supporting development through evolution is needed. In this research a series of building blocks will be developed that can be used to incrementally construct a prototype environment which supports Object-Oriented, iterative development. To develop these building blocks, existing Object-Oriented tools and a spiral lifecycle in which several prototype environments are developed will be used. Thus, this project aims to evolve Object-Oriented technology and spiral development so that a production quality, high productivity environment can ultimately be produced.