SHSelfHostIndex

DAViCal vs Citadel

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?
DAViCal Server for sharing calendars and address books via DAV VS CI Citadel All-in-one groupware, mail and collaboration server
FeatureDAViCalCitadel
Deploy effortUnder-an-hour setupRead-the-docs project
CategoryGroupwareGroupware
LicenseGPL-2.0GPL-3.0
LanguagePHPC
Setup difficultyMediumMedium
Min. RAM256 MB512 MB
Deploymentdocker, bare-metal, sourcebare-metal, source
GitHub stars★ 200★ 100
First released20071987
ReplacesGoogle Calendar, Microsoft ExchangeMicrosoft Exchange, Microsoft 365

What are DAViCal and Citadel?

DAViCal

DAViCal is a mature CalDAV and CardDAV server that stores calendars and address books in a PostgreSQL database. It supports sharing and fine-grained access control between users.

  • CalDAV and CardDAV server
  • PostgreSQL-backed storage
  • Calendar sharing and permissions
  • LDAP authentication support

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

DAViCal vs Citadel: key differences

DAViCal is written in PHP, while Citadel is built with C. Licensing differs — GPL-2.0 for DAViCal versus GPL-3.0 for Citadel. DAViCal is the lighter option, starting around 256 MB of RAM against 512 MB for Citadel. Citadel is the more established project (first released 1987), while DAViCal arrived in 2007. DAViCal has the considerably larger community, at 200 GitHub stars versus 100. DAViCal lists first-class Docker deployment; Citadel does not.

Why pick each one

Choose DAViCal if…

  • Released under the GPL-2.0 license
  • First-class Docker support for quick deployment
  • Written in PHP
  • Tiny footprint — runs in 256 MB RAM

Watch out for

  • Dated administration UI
  • PostgreSQL required
DAViCal details

Choose Citadel if…

  • Single-package setup
  • Low resource needs

Watch out for

  • Niche project
  • Old-fashioned UI
Citadel details

Frequently asked questions

Is DAViCal or Citadel better?

Neither is universally better. DAViCal has the larger community; both share a medium setup difficulty, so the decision comes down to features and licensing.

Are DAViCal and Citadel free and open-source?

Yes. DAViCal is licensed under GPL-2.0 and Citadel under GPL-3.0. Both can be self-hosted at no software cost.

Can I run DAViCal and Citadel with Docker?

DAViCal: yes. Citadel: check the project docs for container support.

Which is lighter on resources, DAViCal or Citadel?

DAViCal has the smaller minimum footprint at 256 MB of RAM, compared to about 512 MB for Citadel. Real-world usage depends on library size, user count, and enabled features.

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