jabber.isc.org

[Stephane Bortzmeyer]

On Mon, Jan 21, 2013 at 04:17:40PM +0100,
 Stephane Bortzmeyer <bortzmeyer at nic.fr> wrote 
 a message of 19 lines which said:

> 1) Choose a XMPP provider. I would recommend Google Talk (gratis,
> very reliable) since this is the one I use. If you don't like/use
> Google, jabber.org offers a gratis service, too. If your
> organization is an OARC member, there is also an OARC XMPP server.

Of course, there is also the possibility of being your own provider
(that's the great thing with the Internet) and install a XMPP server
(there are many implementations) on your machines. I never did it so I
cannot advise.