The WorldChat plugin enhances the chat functionality by ensuring that players can only send and receive chat messages within the same world. This means that if a player is in the Nether, their chat messages will only be visible to other players in the Nether. Similarly, if a player is in the End, their chat messages will only be visible to other players in the End. This feature promotes more immersive and relevant conversations based on the player's current environment. More detailed description here.