LAN Messenger - LAN Messenger is a decentralized UDP IM-style chat client which supports usernames...
MyChat - Secure instant messenger for any network
Bopup IM Suite - Organize secure messaging system and communicate instantly via self-hosted IM server.
BORGChat - BORGChat is a LAN messaging software program.
BeeBEEP - You can message and share files inside your intranet without a server.
BigAnt Office LAN Messenger - BigAnt Office LAN Messenger offers rich features for secure and stable business communication.