DATR was developed in the late 1980s by Roger Evans, Gerald Gazdar and Bill Keller,[2][3] and used extensively in the 1990s; the standard specification is contained in the Evans and Gazdar RFC, available on the Sussex website (below). DATR has been implemented in a variety of programming languages, and several implementations are available on the internet, including an RFC compliant implementation at the Bielefeld website (below).