The principles for enabling children to become fully proficient multilinguals through schooling are well known. Even so, most indigenous/tribal, minority and marginalised children are not provided with appropriate mother-tongue-based multilingual education (MLE) that would enable them to succeed in school and society. Experts from all continents ask why, and show how it CAN be done. The book discusses general principles and challenges in depth and presents case studies from Canada and the USA, northern Europe, Peru, Africa, India, Nepal and elsewhere in Asia. Analysis by leading scholars in the field shows the importance of building on local experience. Sharing local solutions globally can lead to better theory, and to action for more social justice and equality through education.