Citadel vs Radicale
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
Radicale
Simple, lightweight CalDAV and CardDAV server
| Feature | Citadel | Radicale |
|---|---|---|
| Category | Groupware | Groupware |
| License | GPL-3.0 | GPL-3.0 |
| Language | C | Python |
| Setup difficulty | Medium | Easy |
| Min. RAM | 512 MB | 64 MB |
| Deployment | bare-metal, source | docker, bare-metal, source |
| GitHub stars | ★ 100 | ★ 4,877 |
| First released | 1987 | 2008 |
| Replaces | Microsoft Exchange, Microsoft 365 | Google Calendar, iCloud |
Why pick each one
Frequently asked questions
Is Citadel or Radicale better?
Radicale is the stronger all-round pick: it has both the larger community and the simpler easy setup. Consider Citadel if its specific feature set fits your needs better.
Are Citadel and Radicale free and open-source?
Yes. Citadel is licensed under GPL-3.0 and Radicale under GPL-3.0. Both can be self-hosted at no software cost.
Can I run Citadel and Radicale with Docker?
Citadel: check the project docs for container support. Radicale: yes.