The lexical knowledge representation language DATR is arguably the most frequently implemented knowledge representation language in history. The implementers have all been intensive DATR users, and consequently have contributed a wealth of practical wisdom to complement the original logical foundations of DATR.
Compilers and interpreters for the lexical knowledge representation langugage DATR have been implemented in many places and in a variety of programming languages. Most have been in Prolog, including Turbo-Prolog, Poplog-Prolog, A-Prolog, Arity, Sicstus and Quintus Prolog, but Scheme, awk, Pascal and C systems have been developed.
Currently there is no precise specification of DATR which would be comparable to the current standards for languages like C. The nearest to a specification is the DATR Standard Library RFC Version 2.0, which is a requirements specification for general applications of the DATR language and is not intended to address some of the other issues which require decisions to be made in an implementation project and which affect practical issues of compatibility and efficiency. These include: