Research on the development on written language and literacy is inherently multidisciplinary. In this book, leading researchers studying brain, cognition and behavior, come together in revealing how children develop written language and literacy, why they may experience difficulties, and which interventions may help those who struggle. Each chapter provides an overview of a specific area of expertise, focusing on typical and atypical development, providing steps for future research, and discussing practical implications of the work. The book covers areas of bilingualism, dyslexia, reading comprehension, learning to read, atypical populations, intervention, and new media. Thus, the book presents a comprehensive overview of the current state of affairs in this field of research. The various book chapters have been written by researchers who all have collaborated at some point in their careers with Ludo Verhoeven, whose research sets the example for the importance of crossing disciplinary borders to research to take the next, important steps. The combination of the research in this book sets the stage for future research that connects various fields, and hopes to inspire anyone interested in the development of written language and literacy.