This is a Bukkit plugin for Minecraft; See http://bukkit.org/.
Where are the Bukkit DL's!!?!?
These folks are really cagey about the actual releases of Bukkit/Craftbukkit, so here's the links:
Decent tutorial on build environments for Bukkit / Maven:
To install, copy target/AtmCraft.jar to the plugins/ directory where CraftBukkit is running.
Using the correct Bukkit Version
Look at the verison of the "bukkit" artifact ID in pom.xml to see the specific version of Bukkit this is built against, the CraftBukkit version in use should match. For example, "<version>1.7.2-R0.2</version>". To use a new Bukkit version, upgrade this version number. Maven should know to go out to the repository listed in <repositories> and get the new .jar file, which will then be deposited as an "artifact", which on my system is at "~/.m2/repository/org/bukkit/bukkit/".
The plugin runs within the CraftBukkit server, but illustrates calling out to another server which is written in Python. That server is the "ATMCraft" server, available at: