Uses of Interface

Packages that use OfflinePlayer
The root package of the Bukkit API, contains generalized API classes.
Classes used to manipulate the voxels in a world, including special states.
Classes dedicated to handling a plugin's runtime configuration.
Interfaces for non-voxel objects that can exist in a world, including all players, monsters, projectiles, etc.
The interfaces used when manipulating extra data can can be stored inside item stacks.
Interfaces used to manage the client side score display system.