Illustrated Code: Building Software in a Literate Way Andreas Zeller, CISPA Helmholtz Center for Information Security Notebooks – rich, interactive documents that join together code, documentation, and outputs – are all the rage with data scientists. But can they be used for actual software development? In this talk, I share experiences from authoring two interactive textbooks – fuzzingbook.org and debuggingbook.org – and show how notebooks not only serve for exploring and explaining code and data, but also how they can be used as software modules, integrating self-checking documentation, tests, and tutorials all in one place. The resulting software focuses on the essential, is well-documented, highly maintainable, easily extensible, and has a much higher shelf life than the "duct tape and wire” prototypes frequently found in research and beyond.