Development resources

Map File Format
See these pages for information on Map Editing:

Map Editing (general)

Map Editing (hex)

Java Classes to Deserialize Maps

.dat Map Format

Map Format (NBT) 1 2

Java Class to read and write NBT structures

Packet Protocol
Every packet starts with a byte representing the Packet ID.

Mobs

 * See: Mobs

In creative mode, players and monsters are all same. If you want to make a monster, just make a fake player id. Id of monster can be anything. The client finds the skin by the player name - the client just checks url http://minecraft.net/skin/name.png. If file exists, it downloads and uses it. If you want to have a special name and a skin (with normal client), you have to register and pay for an account to upload a skin.

Special names (models for them are hardcoded in client):
 * "zombie"?