According to some users on the KoreanRandom forums, along with mixaill from the XVM team, it appears some hidden significant changes have been made to the game engine in this update. Of note for modders, a number of new functions, classes, and variables were added, the Python version was updated from 2.7.7 to 2.7.18, dynamic linking is now used instead of static linking, and pybind11 is used inside the client. Some big things may be in store for the development of the game, especially that it is not constrained by potato hardware limits anymore (and no more 32bit version). What does this mean? Many mods will be broken with the coming of update 1.18 and will require major changes in order to work again.