Calcom Calendar vs Kontact

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?
FeatureCalcom CalendarKontact
CategoryGroupwareGroupware
LicenseAGPL-3.0GPL-2.0
LanguageTypeScriptC++
Setup difficultyMediumMedium
Min. RAM1,024 MB512 MB
Deploymentdocker, bare-metal, sourcebinary, source
GitHub stars★ 47,334★ 200
First released20212004
ReplacesCalendly, DoodleMicrosoft Outlook

Why pick each one

Choose Calcom Calendar if…

  • Polished modern UX
  • Rich integrations
Calcom Calendar details

Choose Kontact if…

  • Released under the GPL-2.0 license
  • Written in C++
  • Lightweight — runs in 512 MB RAM
Kontact details

Frequently asked questions

Is Calcom Calendar or Kontact better?

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

Are Calcom Calendar and Kontact free and open-source?

Yes. Calcom Calendar is licensed under AGPL-3.0 and Kontact under GPL-2.0. Both can be self-hosted at no software cost.

Can I run Calcom Calendar and Kontact with Docker?

Calcom Calendar: yes. Kontact: check the project docs for container support.

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