Softros LAN messenger - LAN messenger for an internal office chat for home or business users. It does not require a server and is very easy to install and use. It supports personal chats, group chats, message brodcasting, files transfer and remote desktop access.
Dingtone - Dingtone is a free call and texting application for making unlimited calls and text messages to any number at the moment registered in any part of the world by any cellular company.
MyChat - Secure instant messenger for any network
Textnow.com - It lets you text your friends, aka my only source of happiness
BORGChat - BORGChat is a LAN messaging software program.
FluffyChat - Open. Nonprofit. Cute ?