KVIrc 4.3

Programmed in C++, KVIrc (acronym of K-Visual IRC Client) is a graphical IRC client for Windows, Linux, Unix and Mac OS. KVIrc is able to connect to several servers at the same time.
KVIrc has a smart encoding special feature that allows you to use 2 encoding modes at the same time. Also, it supports the mIRC codes for font status, and has its own graphical emoticon and an avatar system, and its own script language, KVS, for user's extensions, addons and scripts (For example, now you can find some KVirc sripts, as Realia script, that make your IRC experience easier, complete and comfortable). Every channel, query and DCC Chat can be encrypted using the Blowfish or the AES/Rijndael system.

With the split window mode, you can divide your channel window into 2 parts, one for the chat messages and one for commands (like joins/parts/mode changes). The size of the windows is variable, so you can hide the command window. Also, Kvirc has some other features, as an mp3 player

The Socket spy helps users to observe the raw communication between client and server for debugging.