3D axis-aligned bounding boxes for Skript.
Create boxes from points, center/size, entities, blocks or Bukkit BoundingBoxes, then test containment and intersection, or combine and expand them. 'point' parameters accept both vectors and locations, since this only needs the xyz component of each.
With pacskage:
/package install https://github.com/miberss/aabb
Public domain (Unlicense).