Zephyr is derived from the original Project Athena 'Instant Message' system and allows users to send messages to other users or to groups of users. Users can view incoming Zephyr messages as windowgrams (transient X windows) or as text on a terminal.

This package provides the server for the messaging service, which maintains a location and subscription database for all the receiving clients. All zephyrgrams are sent to the server to be routed to the intended recipient. Only one server is required for a group of clients.