CraftBukkit

Bukkit is a free, open-source, software project that provides the means to extend the popular Minecraft multiplayer server.

Learning from the mistakes made by other mods, Bukkit aims to be different and fill the void left by them: built from the ground up, focused on performance, ease-of-use, extreme customization and open communication between the Team and you. The overall design of Bukkit has been inspired by other mods and our experience as Minecraft players just like yourselves, giving us a unique perspective and advantage going into the creation of the Bukkit Project.