A Note on IRC EtiquetteThe main error newbies commit on irc, is to ask a question and then leave. If you want to get an answer to your question, keep your window open; it doesn't cost anything. The second newbie error is to ask to ask. You're here to ask questions, so just ask them and then warmly wait for an answer.
A Note on Web InterfaceLibera provides a convenient web interface to log into their network. If you have not used IRC before, this might be the most convenient way to quickly try out IRC. So for example if you want to join the #lisp channel on Libera, you just need to go to https://web.libera.chat/#lisp, enter some arbitrary nick (leave password blank for now) and log in.
This page is a non-exhaustive listing of most of the Common Lisp-related channels that exist on Libera.chat.
General Channels   and now  and inhabits two notable bots: minion (part of cl-irc), responsible for note delivery and frequent questions, and specbot, which helps with Hyperspec references.
Note: #cl-gardeners on freenode, which belonged to the Common Lisp Gardeners Project, is now defunct and has merged with #lispcafe.LispGameDevelopers using various lisp dialects, including Common Lisp. Among other things, the International Lisp Games Expo is coordinated there.SLIME, the Superior Lisp Interaction Mode for Emacs, a popular Lisp programming environment.
Implementation ChannelsABCL developer hangout - Combining CL and Java.Clasp developer hangout - Combining CL and C++ for science.CCL developer hangout, more dev than help.ECL channel for questions and answers here! Come on join now!SBCL developer hangout, more dev than help -- but if #commonlisp can't solve it and it's SBCL specific, we'll try.SICL developer hangout, more dev than help.
Un canal para usuarios de Lisp hispanohablantes (si nadie responde en #lisp-es, puedes llamar a un hispanohablante en #lisp)
A Note about Freenode
Freenode (formerly the Open Projects Network) used to be the older home of Lisp channels. But Freenode has been taken over by a new management. Therefore the staff and communities have moved over to the libera.chat irc server. Libera Chat is now the main IRC network for Lisp related channels. See: The Freenode resignation FAQ, or: "what the fuck is going on?"
CLiki pages about IRC
- beirc - beirc is a CLIM IRC client application using the cl-irc library as a backend, initially written by Gilbert Baumann, now maintained by Dave Murray and others
- Birch - Birch is a simple IRC client library
- cl-irc - cl-irc is an IRC library written in Common Lisp
- Colleen - Colleen is yet another IRC chat bot framework
- girc - gIRC is a basic IRC client application for the terminal
- IRC Quotes - Some moments from IRC, preserved for posterity, some humorous
- irc-logger - irc-logger is a networking library written by Kevin Rosenberg which uses the cl-irc library to provide multichannel Internet Relay Chat (IRC) logging
- Lisp IRC Bots - There are several IRC bots written in Lisp
- lispcafe - #lispcafe on www.libera.chat
- lisppaste - lisppaste sits on a webserver and users can paste text into it
- Maiden - Maiden is a collection of systems to help you build applications and libraries that interact with chat servers
- minion - minion is an IRC robot (who prefers the term "electronically composed.") For online help, try /msg minion help
- trivial-irc - trivial-irc is a small IRC library that provides only very basic facilities for communicating with IRC servers, and has no facilities for extensions like DCC, CTCP etc
- WeirdIRC - WeirdIRC is a simple IRC client using CLIM
- X-Chat Common Lisp Plugin - The X-Chat Common Lisp plugin is a plugin for X-Chat version 2 and up (the famous IRC client) that allows you to use Common Lisp scripts to control X-Chat behaviour