Scryer is not yet as fast or feature-rich as SWI. SWI has been in business for about 30 years longer, so that shouldn't surprise anyone. Also, Scryer is committ

Scryer is not yet as fast or feature-rich as SWI. SWI has been in business for about 30 years longer, so that shouldn't surprise anyone. Also, Scryer is committed to strict conformance to the ISO Prolog standard, which SWI has disregarded for a while now.