Overview of Lion Server’s iChat: Instant Messaging and More

By John Rizzo

The iChat Service in Lion Server provides instant messaging, audio and video conferencing, and file transferring; it supports Mac, Windows, and Linux clients as well as mobile phones. iChat works on a person-to-person basis and in multiuser situations.

iChat Server can also create persistent chat rooms, which let participants leave or log off. When they return, they can see everything that happened in their absence. Users can send chat messages to other users who are offline.

iChat also acts as a kind of automatic note-taking service because users can generate chat transcripts. On the server, you can log chat text so that the administrator can read it or forward it to a group that needs it.

Chats aren’t just text, however. The server and clients support audio and video conferencing using the built-in mics and video cameras of most Macs and iOS devices.

iChat service is private and secure, using Secure Sockets Layer (SSL) encryption. Users must have accounts in (and are authenticated by) the Open Directory domain, which means they can use iChat services from any computer and still see their buddy lists, groups, and other information.

Lion Server’s iChat service is compatible with a number of instant-messaging servers and clients. iChat service is based on the open standard Extensible Messaging and Presence Protocol (XMPP), also called Jabber, which is used in the Jabber and Google Talk servers.

This compatibility enables iChat Server to communicate (or federate) with other XMPP servers or domains, including Google Talk, to enable users of both to interact. XMPP support also means that the server supports Jabber clients on any platform.