Minecraft is a fairly well-known game with many mods. Millenaire is one mod that aims to allow the player to play with or against four cultures, two of which have primary world-quests to complete.
My project is intended to be a full-featured content editor for the Millenaire mod, written in Java ontop of the NetBeans Platform. It will be usable by users on Windows, Linux, and Mac desktops.
For information on the Millenaire mod, see http://www.millenaire.org/
Thank you for your work.