ircu2 vs Spacebar
A side-by-side comparison of two self-hosted chat & communication options — licensing, setup difficulty, resource needs, and what each one replaces.
Spacebar
Self-hostable, open-source Discord-compatible chat backend
| Feature | ircu2 | Spacebar |
|---|---|---|
| Deploy effort | Read-the-docs project | Under-an-hour setup |
| Health score | 51 · Fair | 83 · Excellent |
| Category | Chat & Communication | Chat & Communication |
| License | GPL-2.0 | AGPL-3.0 |
| Language | C | TypeScript |
| Setup difficulty | Medium | Hard |
| Min. RAM | 64 MB | 1,024 MB |
| Deployment | bare-metal, source | docker, source |
| GitHub stars | ★ 64 | ★ 2,196 |
| First released | 1996 | 2021 |
| Replaces | Discord, Slack | Discord |
What are ircu2 and Spacebar?
ircu2
ircu2 (ircd-undernet) is the IRC server daemon developed for and used by the Undernet IRC network. It can be self-hosted to run an IRC network and supports a feature-rich channel and server model.
- IRC server used by Undernet
- Feature-rich channel model
- Lightweight C daemon
Spacebar
Spacebar is a free, open-source, self-hostable chat platform that is compatible with the Discord client and API. It lets communities run their own Discord-like server infrastructure.
- Discord-API compatible
- Works with existing Discord clients
- Self-hosted communities
- Voice and text channels
ircu2 vs Spacebar: key differences
Ircu2 is written in C, while Spacebar is built with TypeScript. Licensing differs — GPL-2.0 for ircu2 versus AGPL-3.0 for Spacebar. Ircu2 is the lighter option, starting around 64 MB of RAM against 1,024 MB for Spacebar. Ircu2 is the more established project (first released 1996), while Spacebar arrived in 2021. Spacebar has the considerably larger community, at 2,196 GitHub stars versus 64. Spacebar lists first-class Docker deployment; ircu2 does not.
Why pick each one
Choose ircu2 if…
- Released under the GPL-2.0 license
- Written in C
- Tiny footprint — runs in 64 MB RAM
Choose Spacebar if…
- Released under the AGPL-3.0 license
- First-class Docker support for quick deployment
- Active community (2.2k GitHub stars)
- Written in TypeScript
Watch out for
- Still in heavy development
- Feature gaps versus Discord
Frequently asked questions
Is ircu2 or Spacebar better?
Neither is universally better. Spacebar has the larger community, while ircu2 is simpler to set up (medium difficulty). Choose based on the comparison table above and your own setup.
Are ircu2 and Spacebar free and open-source?
Yes. ircu2 is licensed under GPL-2.0 and Spacebar under AGPL-3.0. Both can be self-hosted at no software cost.
Can I run ircu2 and Spacebar with Docker?
ircu2: check the project docs for container support. Spacebar: yes.
Which is lighter on resources, ircu2 or Spacebar?
ircu2 has the smaller minimum footprint at 64 MB of RAM, compared to about 1,024 MB for Spacebar. Real-world usage depends on library size, user count, and enabled features.