WeeChat (Wee Enhanced Environment for Chat) is a fast and light IRC client for many operating systems. Everything can be done with a keyboard, and it is customizable and extensible with C plugins and scripts. It is compliant with RFCs 1459, 2810, 2811, 2812, and 2813.
Information regarding Project Releases and Project Resources. Note that the information here is a quote from Freecode.com page, and the downloads themselves may not be hosted on OSDN.