 RPG Maker 2003, also referred to as RM2k3, and sometimes RM2k/3, is largely an improvement of RM2k.RM2k games can be ported to RM2k3 (but not back to RM2k, the conversion is permanent), and most resources are interchangeable.The main difference is the introduction of a side-view battle system similar to that found in the "Final Fantasy" games on the Super NES and the Sony PlayStation.