ergo

Ergo is an IRC server that ships with the parts you used to bolt on yourself. A traditional setup means an ircd, a separate services package for nickname and channel registration, and a bouncer per user so nobody loses scrollback when they close the laptop. Ergo is one Go binary covering all three. MIT, free, no paid edition.

Setup is a binary and a YAML file that rehashes at runtime, so most config changes never drop a connection. History sits in memory by default; point it at MySQL, PostgreSQL, or SQLite to survive restarts. TLS, SASL, bcrypt password hashing, and host cloaking are built in. A small VPS runs it fine.

Solo and small private groups: cheapest self-hosted chat you can stand up in an evening. Teams already on IRC: the built-in bouncer alone justifies dropping ZNC. Anyone shopping for a Slack replacement wants mattermost/mattermost, zulip/zulip, or RocketChat/Rocket.Chat instead.

The catch is IRC. No threads, no file uploads, no reactions you can count on, and what each person sees depends on the client they picked. Ergo modernizes the protocol as far as IRCv3 allows and stays honest about the ceiling. Watch the security releases: the August 2026 patch fixed an account verification bypass.