1)   Outlook LAN Messenger 5.0.0
Instant messaging software designed for use within Small and Corporate Office's Local Area Network. Features include Text & Group Chat, Voice Chat, File Transfer, Offline Messaging. Its Server-less, requires No internet connection & Easy to install.

 2)   Softros LAN Messenger 4.2
Softros LAN Messenger is a instant LAN messaging software for home or office users. It does not require a server and is very easy to install and use. Works on the TCP/IP based networks and supports Windows/Citrix terminal services.

 3)   LanToucher Network Chat 1.0b3
LanToucher Network Chat is small and easy-to-use chat software for your small office or home LAN (Local Area Network). Serverless (P2P) messaging; No dedicated server or Internet connection is required.