*Custom GUI API to make your own screens and HUD elements
*Pre-cache custom textures/sounds/other things your plugin uses on login.
*Custom skins, capes, and multi-line capable titles
*Custom achievement notifications
*Play Minecraft sound effects and music
*Play custom sound effects and music
*Stop music playback with fade out

*Maximum/minimum fog levels
*Custom item hover-over names
*Custom item textures
*Clipboard get/set
*Control texture packs
*Control cloud height/visibility
*Control star frequency
*Control sun and moon texture and size
*Control sky and cloud colors
*Control weather rendering for biomes
*Control jump height
*Control gravity
*Control speed in air, on the ground, and while swimming
*Server reconnect API