Citadel vs Nextcloud Groupware
A side-by-side comparison of two self-hosted groupware options — licensing, setup difficulty, resource needs, and what each one replaces.
Not the right match-up?
Citadel
All-in-one groupware, mail and collaboration server
VS
Nextcloud Groupware
Mail, calendar and contacts bundle for Nextcloud
| Feature | Citadel | Nextcloud Groupware |
|---|---|---|
| Category | Groupware | Groupware |
| License | GPL-3.0 | AGPL-3.0 |
| Language | C | JavaScript |
| Setup difficulty | Medium | Medium |
| Min. RAM | 512 MB | 1,024 MB |
| Deployment | bare-metal, source | docker, bare-metal, source |
| GitHub stars | ★ 100 | ★ 1,169 |
| First released | 1987 | 2016 |
| Replaces | Microsoft Exchange, Microsoft 365 | Microsoft 365, Google Workspace |
Why pick each one
Choose Nextcloud Groupware if…
- Tight Nextcloud integration
- Standards-based sync
Frequently asked questions
Is Citadel or Nextcloud Groupware better?
Neither is universally better. Nextcloud Groupware has the larger community; both share a medium setup difficulty, so the decision comes down to features and licensing.
Are Citadel and Nextcloud Groupware free and open-source?
Yes. Citadel is licensed under GPL-3.0 and Nextcloud Groupware under AGPL-3.0. Both can be self-hosted at no software cost.
Can I run Citadel and Nextcloud Groupware with Docker?
Citadel: check the project docs for container support. Nextcloud Groupware: yes.