Citadel vs Tine
A side-by-side comparison of two self-hosted groupware options — licensing, setup difficulty, resource needs, and what each one replaces.
| Feature | Citadel | Tine |
|---|---|---|
| Deploy effort | Read-the-docs project | Under-an-hour setup |
| Category | Groupware | Groupware |
| License | GPL-3.0 | AGPL-3.0 |
| Language | C | HTML |
| Setup difficulty | Medium | Medium |
| Min. RAM | 512 MB | 1,024 MB |
| Deployment | bare-metal, source | docker, bare-metal |
| GitHub stars | ★ 100 | ★ 22 |
| First released | 1987 | 2007 |
| Replaces | Microsoft Exchange, Microsoft 365 | Microsoft 365, Google Workspace |
What are Citadel and Tine?
Citadel
Citadel is a mature, all-in-one collaboration suite that integrates email, calendaring, address books, instant messaging, and bulletin boards. It is designed for easy installation and minimal maintenance.
- Integrated mail and calendar
- Built-in groupware web client
- Instant messaging and forums
- Easy installer
Tine
Tine, formerly Tine 2.0, is a web-based groupware and CRM platform combining email, calendar, contacts, tasks, and customer relationship management. It targets small and medium businesses.
- Integrated groupware and CRM
- ActiveSync support
- Shared calendars and addressbooks
- Modular application structure
Citadel vs Tine: key differences
Citadel is written in C, while Tine is built with HTML. Licensing differs — GPL-3.0 for Citadel versus AGPL-3.0 for Tine. Citadel is the lighter option, starting around 512 MB of RAM against 1,024 MB for Tine. Citadel is the more established project (first released 1987), while Tine arrived in 2007. Citadel has the considerably larger community, at 100 GitHub stars versus 22. Tine lists first-class Docker deployment; Citadel does not.
Why pick each one
Choose Citadel if…
- Single-package setup
- Low resource needs
Watch out for
- Niche project
- Old-fashioned UI
Choose Tine if…
- Released under the AGPL-3.0 license
- First-class Docker support for quick deployment
- Written in HTML
Watch out for
- Smaller community
- Documentation mostly in German
Frequently asked questions
Is Citadel or Tine better?
Neither is universally better. Citadel has the larger community; both share a medium setup difficulty, so the decision comes down to features and licensing.
Are Citadel and Tine free and open-source?
Yes. Citadel is licensed under GPL-3.0 and Tine under AGPL-3.0. Both can be self-hosted at no software cost.
Can I run Citadel and Tine with Docker?
Citadel: check the project docs for container support. Tine: yes.
Which is lighter on resources, Citadel or Tine?
Citadel has the smaller minimum footprint at 512 MB of RAM, compared to about 1,024 MB for Tine. Real-world usage depends on library size, user count, and enabled features.