Book excerpt: Within bilingual education, more and more programs are adopting the option of immersion education, in which a second language is used as the medium of instruction. This volume illustrates the implementation immersion education in North America, Europe, Asia, the Pacific, and Africa, showing its use in programs ranging from preprimary to tertiary level and demonstrating how it can function in foreign language teaching, for teaching a minority language to members of the language majority, for reviving or supporting languages at risk of extinction, and for helping learners acquire a language needed for wider communication or career advancement. A final section reviews lessons learned from experiences with immersion and explores new directions the approach is taking. This text will be of interest to teachers, teacher educators, and others involved in bilingual education.