ISO PrologDialect of programming language Prolog
ISO Prolog is a standard which defines Prolog language. It consists of two parts.
ISO/IEC 13211-1 was published in 1995, though the work on it started as early as 1984. It was meant to clarify ambiguous aspects of the language, standardize the existing implementations of Prolog and make them, as well as the later implementations, compatible.
ISO/IEC 13211-2, published in 2000, added support for modules to the standard.