The text editor and kitchen sink GNU emacs has a obscure, but built-in IRC client in the form of ERC.
ERC is included by default in v22.3 and above of GNU emacs, but some distributions may place it in a seperate package.
While ERC is primarily of interest to users of GNU emacs, it a fully functional, mature IRC client, with a small but dedicated community.
ERC is accessible inside emacs via the command “
Upon starting erc, prompts for the server to connect to appear in the emacs minibuffer.
Once the connection settings are entered, the client connects automatically, and an ERC > prompt appears in the buffer, where standard IRC commands can be entered. Channels and queries are opened as emacs buffers.
More information can be found on the emacs wiki