An interface between Prologapplication programs and the X Window System that aims to be independent from the Prologengine, provided that IT has a Quintus {foreign function} interface (e.g. {SICStus} and {YAP}). IT is mostly wrITten in Prolog and is divided in two libraries: Edipo - the lower level interface to the Xlib functions and YtoolkIT - the higher level user interface toolkIT. . E-mail: Ze' Paulo Leal . (1993-03-02)