GNU Prolog is a native Prolog compiler with constraint solving over
finite domains (FD) developed by Daniel Diaz
(http://loco.inria.fr/~diaz).

GNU Prolog is a very efficient native compiler producing (small)
stand-alone executables. GNU-Prolog also offers a classical
top-level+debugger.

GNU Prolog conforms to the ISO standard for Prolog but also includes a
lot of extensions (global variables, DCG, sockets, OS interface,...).

GNU Prolog also includes a powerful constraint solver over finite
domains with many predefined constraints+heuristics.