This is an example ERC session which shows how to connect to the ‘#emacs’ channel on Libera.Chat. Another IRC channel on Libera.Chat that may be of interest is ‘#erc’, which is a channel where ERC users and developers hang out. These channels used to live on the Freenode IRC network until June 2021, when they—along with the official IRC channels of the GNU Project, the Free Software Foundation, and many other free software communities—relocated to the Libera.Chat network in the aftermath of changes in governance and policies of Freenode in May and June 2021. GNU and FSF’s announcements about this are at https://lists.gnu.org/archive/html/info-gnu/2021-06/msg00005.html, https://lists.gnu.org/archive/html/info-gnu/2021-06/msg00007.html, and https://lists.gnu.org/archive/html/info-gnu-emacs/2021-06/msg00000.html.
Run M-x erc. Use “irc.libera.chat” as the IRC server, “6667” as the port, and choose a nickname.
Switch to the “irc.libera.chat:6667” buffer, if you’re not already there. You will see first some messages about checking for ident, and then a bunch of other messages that describe the current IRC server.
In that buffer, type “/join SPC #emacs” and hit RET. Depending on how you’ve set up ERC, either a new buffer for “#emacs” will be displayed, or a new buffer called “#emacs” will be created in the background. If the latter, switch to the “#emacs” buffer. You will see the channel topic and a list of the people who are currently on the channel.
If you would like to be able to talk with people privately on the Libera.Chat network, you will have to “register” your nickname. To do so, switch to the “irc.libera.chat:6667” buffer and type “/msg NickServ register <password>”, replacing “<password>” with your desired password. It should tell you that the operation was successful.
If you switch back to the “#emacs” buffer, you can type a message, and everyone on the channel will see it.
If you want to talk with someone in private (this should usually not be done for technical help, only for personal questions), type “/query <nick>”, replacing “<nick>” with the nickname of the person you would like to talk to. Depending on how ERC is set up, you will either see a new buffer with the name of the person, or such a buffer will be created in the background and you will have to switch to it. Begin typing messages, and you will be able to have a conversation.
Note that if the other person is not registered, you will not be able to talk with them.