mIRC is a shareware IRC client for Windows. mIRC is a highly configurable IRC client with all the goodies other clients on UNIX, Macintosh and even on windows offer, combined with a clean user interface. mIRC offers full color text lines, DCC File Send and Get capabilities, programmable aliases, a remote commands and events handler, place sensitive popup menu's, a great Switchbar, World Wide Web and sound support, and... a lot more. mIRC is shareware but not crippled in any way.

Download : http://www.mirc.com/get.html
Changelog : http://www.mirc.co.uk/whatsnew.txt