Software engineering is hampered by the fact that software systems quickly become so complex that they are hard to understand, evolve and maintain. Closer integration of code and model helps, because the model serves as a map to the code and the code fills in the details for the model. Simultaneously, one avoids consistency problems. TUBE, a programming language and an integrated environment, achieves this integration by using topic maps to manage both code and data (including meta-data and non-code artifacts). This enhanced expressiveness is complemented by an interactive way of system construction that cannot be achieved by static programming languages. KEY WORDS Software Design and Development, Software Development, Prototype-Based Object-Oriented Programming, Model Integration