I'd additionally suggest joining the SWI Prolog board. They are a kind and generous community. Jan Wielemaker -- the principal contributor -- often answers questions directly.
Meanwhile, SWI Prolog is a mature and commercially used open-source Prolog distribution. It has a huge number of libraries which will come in useful for real world applications.
Meanwhile, SWI Prolog is a mature and commercially used open-source Prolog distribution. It has a huge number of libraries which will come in useful for real world applications.