LanToucher messenger is used for exchange instant messages in your local network users, so you can see someone’s favorite contact in their contact list and also able to send messages to selected users and make a conference room.
Features in LanToucher
LanToucher use technology of P2P (Peer to Peer) you can communicate directly with your colleague. Another features in LanToucher, you can modify your contacts with custom image profile, sounds, and colorful text messages so it will be more fun.
Compatibility of Operating System
LAN Toucher is able to work over these OS: …

Fomine is simple LAN Messenger Client with one Chat Room. It’s connected securely. Features: Chat Messages outgoing and incoming message, Status Message Online, Away, or disconnected. It has Clear Interface. Fomine LAN Chat Works for Windows 98, NT, 2000, ME, XP, and Vista.
Download: Fomine LAN Chat
License: Freeware
Website:http://www.fomine.com/lan-chat.html

KouChat is free GNU GPL V2 Chat client for Local Area Networks that did not need any server to operate it. It can be said that Kouchat is LAN Serverless Chat Client. Features available in Kouchat are: Main chat Window, Private Message Chat, Color Text, Smileys Emoticons, Away Message, Topic, File Transfer, Sound Notification, Logging and many more. It works under Windows or Linux or even Mac OS X. Required Java SE 6.

Download: KouChat
License: GNU GPL
Website: http://code.google.com/p/kouchat/