World type

World Type is an option for World Generation first introduced in Snapshot 12w01a. It allows the player to create worlds of specific type as provided. It currently offers the types Default and Superflat.

Hybrid(Quarry)

 * Well there is a possibility(if you mix up the right files in the save folder) to make a hybrid-Quarry world.

Default

 * This was the only available world type until the release of Minecraft 1.1, adding Superflat worlds.

Superflat

 * In Superflat World type, the Void appears sky color from above Y coordinate 0. However, when viewed from below this coordinate, the Void appears its normal black color.
 * Slimes are very common on Superflat worlds, as the ground level is only 4 blocks above the bottom and slimes spawn from layers 40 to the bottom.
 * Villages spawn rates are somewhat increased when using this world type.

Hybrid

 * An user called AndGeo seems like found about hybrid worlds out first.
 * Good because of both components default and superflat.
 * Hybrid worlds are called by users Quarry-worlds because they look like giant quarrys.