Now I know you may not be interested in adding more mappers, but please consider this: What if you enabled Jnes to use dll plugins for mapper support? Maybe then it would be possible for you to enable Jnes to support NESten's v 1.3 open source mapper plugin? This would allow Jnes to support a lot more mappers, if the user wishes to download the NESten mappers anyway. You could use a default mapper plugin for the mappers Jnes currently supports. Do you think this could work?