[a-french-anon]

No idea, but it might be worth looking into Mercury and {mini,micro}Kanren/core.logic as more practical iterations on it (either by adding things to Prolog or extracting the interesting to stuff to use in more general purpose languages).

[Avshalom]

At the end of the day "practical" means library support and community knowledge, by which measure Prolog and more specifically SWI and Sicstus are far more practical than any of the other logic languages or implementation options

[harperlee]

Well if your problem does not require a solution that’s 100% written in prolog, then any relational/CLP system that can be hosted or work as a library is going to win in terms of library support and community knowledge, at solution level.

So e.g. a core.logic solution can make extensive use of the jvm ecosystem.