0irc is the smallest known (IRC) Internet Relay Chat client in the world for windows. Not only does it have a small footprint, but also contains a small set of necessary features. Features such as chat, dcc file transfers, multiple server connections and an all channel overview. 0irc is command line based with no menu, so it't meant for those who already know their way around IRC Clients. 0irc requires only 172KB for complete installation.
Oirc - Portable IRC Screenshot:
Authors Website: Project Page
License: Open Source
Download: Grab this Portable 0IRC Client HERE