Machine translation – the use of computers to translate automatically among human languages – is an alluring prospect, one that for more than 50 years has fascinated researchers, inspired idealists and opportunists, and provoked unease among professional translators. This article gives a broad survey of this diverse and active field. It begins with a description of the many challenging problems faced by designers of machine translation systems and explains why there appears to be slim hope of attaining human-level performance in the foreseeable future. With these problems in mind, this article examines the main symbolic and empirical translation methods, and tries to give a balanced picture of their strengths and weaknesses.