Uses of Interface

Packages that use InventoryHolder
The root package of the Bukkit API, contains generalized API classes.
Classes used to manipulate the voxels in a world, including special states.
Interfaces for non-voxel objects that can exist in a world, including all players, monsters, projectiles, etc.
Interfaces for various Minecart types.
Events triggered by various world states or changes.
Classes involved in manipulating player inventories and item interactions.