Children are becoming increasingly important as a separate user group of software and websites. However, the differences between children and adults in terms of their cognitive, motor, emotional, and social development are so considerable that the existing findings on ergonomic design cannot be directly transferred to software and websites for children. To fill this gap, Janine Liebal and Markus Exner, based on extensive analytical and empirical research, provide a catalog of 110 design recommendations as well as useful tips and techniques for involving children as informants, users, design partners, and testers in the development process of software and websites.