ERC is an IRC client for Emacs/XEmacs. It supports multiple channel presence, elaborate faces' setup, pals' list, and some other nice features. It's capabilities should be sufficient for most of IRChatters.
Open source project that offer summary and download services on this page is a project that carry out their development work on other open source development sites. Their work is linked to this page via a feature called OFI, and their work is not carried out here on OSDN site.