This book addresses the gap between Computer-Assisted Language Learning (CALL) materials development and its theoretical considerations by offering a comprehensive look into theory, practice, and research on materials development and content authoring for language instruction/practice, drawing on the author's personal experiences along with previous empirical/theoretical research in CALL materials development, content authoring, language teacher education, and e-learning. The book features four sections. In addition to highlighting related theoretical underpinnings, key concepts, linguistic-didactic functionalities and interaction scenarios in materials development, the volume will address the practical issues and considerations not only in the design, development, integration, and evaluation of the technology-enhanced materials development for language instruction but also the protection, usability, and access in authored and/or co-authored content. Furthermore, previous research findings and foci are addressed to highlight the research gaps and pedagogical implications for materials developers, policy makers, and language teachers. The book can help teachers, educators, and researchers overcome the aforementioned problem by providing a step-by-step guideline on how to effectively integrate technology and design and develop instructional materials for online language instruction and practice.