Colloquy is an advanced IRC & SILC client which aims to fill a void left by unglamorous clients.
By adhering to OS X interface conventions, Colloquy has the look and feel of a quality Mac application.
Colloquy lets you select the style in which the messages are shown.
There are seven styles in total included in the program, with some of them including group messages.
In all Colloquy is very interested and elegant chat client that would score much higher if it supported audio and video but as it is, it’s a great chat only client.
Jitsi Publisher’s Description Jitsi (formerly SIP Communicator) is a cross-platform and free Java based audio/video Internet phone and instant messenger. Jitsi is Open Source / Free Software, and is available under the terms of the LGPL and performs secure video calls, conferencing, chat, desktop sharing, file transfer, support for your favorite OS, and IM network.
TeamSpeak continues the legacy of the original TeamSpeak communication system previously offered in TeamSpeak Classic (1.5) and TeamSpeak 2. TeamSpeak 3 is not merely an extension of its predecessors but rather a complete rewrite in C++ of its proprietary protocol and core technology. TeamSpeak is a flexible, free, easy to use, powerful, and scalable application