.NBT File Extension
File TypeMinecraft Named Binary Tag File
What is an NBT file?
Data file format used by Minecraft, a open-ended 3D world building and exploration game; saves data in the Named Binary Tag (NBT) format, which is a simple binary format developed to store large amounts of binary data; used for storing world, or level, information.
The NBT format can be read by software APIs such as JNBT (The Java NBT Library).