I did a university module in Prolog (for programming intelligent systems). Although I have not used it since, I always remember it fondly. It is a totally different paradigm to the Pythons/Rubies/Cs/Javas and really quite refreshing when you get in to it.
Unfortunately I now struggle to think of a use for it on a day to day basis.
Unfortunately I now struggle to think of a use for it on a day to day basis.