"According to the Radicati Group Inc., a messaging and
collaboration research firm, 45 percent of corporations are already
deploying enterprise instant messaging for faster intraoffice
communications. If you're looking for an open source alternative to
IM products from IBM, Oracle, and Microsoft, consider Jabber's
Extensible Communications Platform (XCP). Setting up a Jabber IM
server isn't as cumbersome as it used to be a few years ago. Here's
how to do it.
"The components you need include a Jabber server (I recommend
jabberd2), a Jabber client or other IM client that understands the
Jabber protocol, and, potentially, LibIDN, if it's not included
with your Linux distribution. LibIDN provides support for IETF
Internationalized Domain Names. You also need a database (either
MySQL, PostgreSQL, Berkeley DB) for storing jabberd data such as
usernames and passwords..."