The book addresses graduate students and practitioners with a basic understanding of "classical" text retrieval methods. The growing amount of non-English information accessible globally and the increased world-wide exposure of enterprises means that these target groups will have a rapidly growing need to adapt their existing knowledge of IR methods to new, multilingual settings. We intend to close the gap between the material covered by most of the classical IR textbooks and this new operational reality. A comprehensive coverage of cross-language and multilingual retrieval technologies will be provided, including a number of advanced topics, such as system evaluation, filtering and question answering in the multilingual context. Attention will be given to both research and practical aspects.