Thanks Samuel,

but I don't think that is what I need.

My question was "Is it possible to implement a Java-based application (service) that uses another database/reasoner instead of SMW one" ?

This is because everything is coded in PHP, so I don't know whether the architecture is "loosely coupled" and I can replace a part of the SMW with my own part (Java app).

So, I want to know whether I need a PHP API or smth similar if I program in Java?