Languages: EN / FR / PL / IT / ES / DK
Compatibility: Windows 95/98/Me/2000/XP/2003/Vista/7/8/
License: Freeware.
Description: A small, fast application designed to be a powerful IRC client

AdiRC is a handy and useful application designed to help you easily connect to a channel / server and start chating with your friends. AdiRC is a small and fast application designed to be a powerful IRC client.

AdiIRC stores all its settings in text files, this way you can grab the adiirc folder and put in on a usb device or external harddrive. Take all your settings and servers with you everywhere!

Softpedia

Website : http://www.adiirc.com
Download page: http://www.adiirc.com/download.php

My opinion: it is very light and powerful irc client, a true alternative to mIRC for Windows platform. Love the extensive options to customize and the initial MSL support (mIRC Scripting Language).