The project was started in 1998 by Jeremy Miller, and the first major public release of the software occurred in May 2000. The main product is jabberd, a server to which jabber clients connect in order to chat. This server can either create a private Jabber network, for instance behind a firewall, or it can join the global public Jabber network.
A key concept of the Jabber system is that of transports, also known as gateways, which allow users to access networks using other protocols - such as AIM, ICQ, MSN / Windows Messenger, or Yahoo! Messenger. Unlike multi-protocol clients, such as Trillian or GAIM, Jabber provides this access at the server level, by communicating via special gateway services running on a remote computer. Any Jabber user can 'register' with one of these gateways by providing the information needed to log on to that network, and can then communicate with users of that network as though they were Jabber users. This means that any client which fully supports the Jabber protocol can be used to access any network to which a gateway exists, without the need for any extra code in the client.
The Jabber protocol, now managed by the Jabber Software Foundation, has been submitted as an IETF draft under the name XMPP, so it can become the official standard for instant messaging. However, SIMPLE, based on the SIP protocol, is competing for the same status.
Some popular jabber clients: