Office Communications Server 2007 R2 Group Chat Server is a new server role in Office Communications Server 2007 R2. This server role provides the platform for group chat rooms, which allow for persistent, ongoing IM conversations. Chat rooms are particularly useful for ongoing collaboration among project team members because all data that is part of the IM conversation in a chat room persists. The Group Chat Server instantiates the chat room, manages its permissions, and maintains its state for the duration of the chat room.