aTalk - An encrypted instant messaging with video call and GPS features for android.
LAN Messenger - LAN Messenger is a decentralized UDP IM-style chat client which supports usernames...
Talk360 - Talk360 is a best-in-class communication utility that offers a convenient way to connect with loved ones globally.
MyChat - Secure instant messenger for any network
FluffyChat - Open. Nonprofit. Cute ?
BORGChat - BORGChat is a LAN messaging software program.