1. GNU Prolog compiler. GNU Prolog is a free Prolog compiler with constraint solving over finite domains (FD) developed at INRIA by Daniel Diaz. GNU Prolog is based on two systems developed by the same author (with lot of code rewriting and a lot of new extensions): wamcc and clp(FD). A lot of work has been devoted to the ISO compatibility, GNU Prolog is very close to the ISO standard, full compliance being one of its goals. From Debian 3.0r0 APT