Jabber is an instant messaging system: it allows people to communicate in real time over the Internet and see when contacts are online. Jabber has many advantages compared to other IM systems like MSN. Opportunity to create their own chat room, (the administrators are at your disposal in case of problems), but also to communicate to other networks such as MSN, ICQ, and Yahoo.
Registration on the server is open and free. Registration can be done via the registration form on the site or jabber client you use to connect. Download can be found on the website a list of available client jabber to join your friends.