BuzzTalk - BuzzTalk is Indian vernacular smart instant messenger
LAN Messenger - LAN Messenger is a decentralized UDP IM-style chat client which supports usernames...
Signal - Fast, simple & secure messaging. Privacy that fits in your pocket.
MyChat - Secure instant messenger for any network
OfficeChat - OfficeChat is a secure messaging app to share rich messages, documents, pictures, videos and location with their colleagues.
BORGChat - BORGChat is a LAN messaging software program.