Baraza is a free mobile instant messaging server for Linux, supporting the Open Mobile Alliance's Instant Messaging and Presence Service (IMPS) protocols (also known as "Wireless Village"). IMPS is supported natively by a wide variety of mobile phones (particularly Nokia and SonyEricsson). The server also supports Jabber/XMPP messaging for inter-domain message exchange (a.k.a. federation).
YSM (You Sick Me) v7 is an ICQ console client. It was originally meant to run in Linux, but it has been successfully tested in Linux, BSD, Win32, BeOS, and QNX. The client requires no extra libraries, and is written in the C language. YSM is based on the last ICQ protocol version, v7/8.
Gizmo Project is a program that uses advanced VoIP technology to allow you to talk with your friends around the world. Gizmo Project uses your Internet connection to make calls to people using other computers. It is simple, and allows you to talk clearly and for as long as you want.