1. original "Instant Message" system-server without Kerberos You probably only need one server for a group of clients. This can be a memory-intensive server, especially for very large sites. The server 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. This is the Project Athena Zephyr notification system 2000/04/21 snapshot. Zephyr 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. From Debian 3.0r0 APT