This is an IRC server that runs on Ergo, which has "Bleeding-edge IRCv3 support", including message history (assuming your IRC client supports it).
To connect, point your IRC client of choice towards irc.swirly.moe, with ports 6667 for plaintext or 6697 for TLS-encrypted.
If you don't know what these words mean we have a selection of web-based IRC clients below.