In the introduction to this chapter John Hutchins distinguishes three types of translation demand: dissemination, assimilation, and interchange. The first one is the demand for translations of a quality normally expected from human translation. The second one is the demand for translations at a somewhat lower level, intended for users who want to access the content of a document as quickly as possible. The third type is that for translations between participants in one-to-one communication. In the second section a typology of systems is presented. The following types are discussed: 1) mainframe, workstation and/or client-server systems on intranets of large organisations, 2) MT systems for professional translators, 3) translator’s workstations; 4) computerised translation; 5) MT systems for occasional users; 6) systems designed for Internet use; 7) MT services on the Internet providing translations on demand. The last part of the chapter discusses the language coverage of Mt systems.