SHSelfHostIndex

OpenCalendar Sync vs ETAR

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?
OP OpenCalendar Sync Self-hosted shared calendar with public event pages VS ET ETAR Open-source calendar server companion for events
FeatureOpenCalendar SyncETAR
CategoryCalendar & ContactsCalendar & Contacts
LicenseMITGPL-3.0
LanguageTypeScriptJava
Setup difficultyMediumMedium
Min. RAM256 MB256 MB
Deploymentdocker, sourcedocker, source
GitHub stars★ 852★ 2,565
First released20142016
ReplacesCalendly, Google CalendarGoogle Calendar

Why pick each one

Choose OpenCalendar Sync if…

  • Released under the MIT license
  • First-class Docker support for quick deployment
  • Written in TypeScript
  • Tiny footprint — runs in 256 MB RAM
OpenCalendar Sync details

Choose ETAR if…

  • Open ecosystem
  • No vendor lock-in
ETAR details

Frequently asked questions

Is OpenCalendar Sync or ETAR better?

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

Are OpenCalendar Sync and ETAR free and open-source?

Yes. OpenCalendar Sync is licensed under MIT and ETAR under GPL-3.0. Both can be self-hosted at no software cost.

Can I run OpenCalendar Sync and ETAR with Docker?

OpenCalendar Sync: yes. ETAR: yes.

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