calcurse vs OpnForm

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

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FeaturecalcurseOpnForm
CategoryCalendar & ContactsCalendar & Contacts
LicenseBSD-2-ClauseAGPL-3.0
LanguageCPHP
Setup difficultyEasyMedium
Min. RAM16 MB512 MB
Deploymentbinary, sourcedocker
GitHub stars★ 1,301★ 3,545
First released20042026
ReplacesGoogle Calendar

Why pick each one

Choose calcurse if…

  • Released under the BSD-2-Clause license
  • Easy to set up — beginner-friendly
  • Active community (1.3k GitHub stars)
  • Written in C
calcurse 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 calcurse or OpnForm better?

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

Are calcurse and OpnForm free and open-source?

Yes. calcurse is licensed under BSD-2-Clause and OpnForm under AGPL-3.0. Both can be self-hosted at no software cost.

Can I run calcurse and OpnForm with Docker?

calcurse: check the project docs for container support. OpnForm: yes.

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