Minecraft server installation on Ubuntu

Installation instructions:

First step, prepare the system requirements:

• sudo apt-get update [This updates all the packages on the server]
  
• java -version [checks if you have Java installed on the machine]
  
• sudo apt-get install default-jdk [installs the necessary Java executables]

Second step, open the server port for inbound communication:

• sudo iptables -A INPUT -p tcp --dport 25565 -j ACCEPT
  

Third step, install the Mindcraft server

• cd /var
  
• mkdir minecraft
  
• cd mincraft
  
• wget https://s3.amazonaws.com/MinecraftDownload/launcher/minecraft_server.jar
  

Fourth step, running the server:
there are two options to run
directly running the server:

• java -Xmx1024M -Xms1024M -jar minecraft_server.jar nogui
  

or run it through a delegation software (this enables the console to be closed without shutting down the server)
for this option, first install "Screen":

• sudo apt-get install screen
  

running the server through Screen:

• screen -S "Minecraft server"
  

detach consule from server stdout:

• ctl-a d
  

or, reattach the console to the Screen stdout:

• screen -R
  

Server's world (level) and player manipulation

the minecraft server has several configuration files that define the game environment characteristics.
these files are saved in a proprietary format and zipped, so there is no use trying to open them in a text editor. the NBT spec is available at: http://wiki.vg/NBT

its possible to run a specialized editor for NBT formatted files available at: https://github.com/jaquadro/NBTExplorer

There are some libraries available for reading and writing to this format in an array of programming languages.

A ruby lib to read/write NBT format files: https://github.com/mental/nbtfile.git
(an extended list is available on the http://wiki.vg/NBT page)