The status of English language has changed over the years as a tool for international communication and as a language for empowerment and social development. Traditional language curriculum development approaches are no longer adequate, as the classroom practice does not strengthen only language proficiency, but rather the perspective of critically literate language learners. This book, therefore, provides a new approach to the language curriculum development. The approach rests on the premise that principles underlying decisions made in the curriculum planning process will have a significant impact on the effectiveness of the curriculum. This volume provides a systematic analysis of philosophies and theoretical principles that decision-makers need to consider. Drawing from the example of Thailand, a comprehensive analysis of the national curriculum planning process will strongly enhance our understanding of the language curriculum development. This book will become an essential reference for policymakers, curriculum developers and will be useful to professionals in TESOL and ELT, as well as for those specifically interested in the Thai foreign language curriculum.