The Oxford Handbook of Endangered Languages, in thirty-nine chapters, provides a comprehensive overview of the efforts that are being undertaken to deal with this crisis. Its purposes are (1) to provide a reasonably comprehensive reference volume, with the scope of the volume as a whole representing the breadth of the field; (2) to highlight both the range of thinking about language endangerment and the variety of responses to it; and (3) to broaden understanding of language endangerment, language documentation, and language revitalization, and, in so doing, to encourage and contribute to fresh thinking and new findings in support of endangered languages.