Prolog is really great for some applications. I used it in robotics and RoboCup@Home. The robot built a world model of its surroundings and labeled entities with classes. When a cleanup tasks was given, the robot picked something up, and based on the class, it reasoned where the entity should be moved (e.g table, kitchen or trashbin).

This was in a mechanical engineering group, so it took some time for some people to get used to such e different language.