LAN Spirit

Lan Spirit is a secure real-time communications application designed for Business networks. It is composed of a server and as many clients as you need. With a LAN Spirit Server started, you can communicate with your co-workers by peer-to-peer chatting or through chat rooms. And you can even invite anyone who is not online to join in your discussion by windows messenger embedded in the Lan spirit.
Lan Spirit Server is native-built and can run smoothly on Windows, Linux, UNIX, and more other OS. Lan Spirit Client runs on Windows OS, and it can also run quit smoothly on Linux through wine. Multi-platform supporting makes Lan Spirit adaptable in various environments. You can seek out anyone easily in the LAN, no matter him/her is currently on Linux KDE or on Windows XP.
Lan Spirit Server can provide services at as many IP addresses as bound on its local machine at the same time. The system administrator can stop/restart services at specified IP separately with services on other IP addresses running normally.
Lan Spirit provides powerful text editing capability. You can use any format of text when you are chatting and can import any face either provided by Lan spirit or customized by yourself. All the messages both on peer-to-peer chatting and on room discussion are transferred encrypted.

Trial version Ограничения:

100 users.