XChat for Windows

XChat (Internet Relay Chat) is a very popular client. It supports multiple servers, has a tabbed interface or a tree interface and is highly configurable.

XChat is an IRC client that offers all the basic functions of other IRC clients. It includes CTCP, DCC file transfer and chats.

It supports plugins for many languages (including C++, Perl and Python, Tcl and Ruby), as well as CLISP, DMDScript, D, and DMDScript. XChat's functionality and features can be customized by writing plugins.