GNOME Calendar vs OpnForm

A side-by-side comparison of two self-hosted calendar & contacts options — licensing, setup difficulty, resource needs, and what each one replaces.

Not the right match-up?
FeatureGNOME CalendarOpnForm
CategoryCalendar & ContactsCalendar & Contacts
LicenseGPL-3.0AGPL-3.0
LanguageCPHP
Setup difficultyEasyMedium
Min. RAM256 MB512 MB
Deploymentbinary, sourcedocker
GitHub stars★ 300★ 3,545
First released20152026
ReplacesGoogle Calendar

Why pick each one

Choose GNOME Calendar if…

  • Released under the GPL-3.0 license
  • Easy to set up — beginner-friendly
  • Written in C
  • Tiny footprint — runs in 256 MB RAM
GNOME Calendar details

Choose OpnForm if…

  • Released under the AGPL-3.0 license
  • First-class Docker support for quick deployment
  • Active community (3.5k GitHub stars)
  • Written in PHP
OpnForm details

Frequently asked questions

Is GNOME Calendar or OpnForm better?

Neither is universally better. OpnForm has the larger community, while GNOME Calendar is simpler to set up (easy difficulty). Choose based on the comparison table above and your own setup.

Are GNOME Calendar and OpnForm free and open-source?

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

Can I run GNOME Calendar and OpnForm with Docker?

GNOME Calendar: check the project docs for container support. OpnForm: yes.

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