OpenCalendar Sync vs Horde Kronolith
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?
OpenCalendar Sync
Self-hosted shared calendar with public event pages
VS
Horde Kronolith
Calendar application from the Horde groupware suite
| Feature | OpenCalendar Sync | Horde Kronolith |
|---|---|---|
| Category | Calendar & Contacts | Calendar & Contacts |
| License | MIT | GPL-2.0 |
| Language | TypeScript | PHP |
| Setup difficulty | Medium | Hard |
| Min. RAM | 256 MB | 256 MB |
| Deployment | docker, source | bare-metal |
| GitHub stars | ★ 852 | ★ 10 |
| First released | 2014 | 2003 |
| Replaces | Calendly, Google Calendar | Google Calendar, Exchange |
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
Choose Horde Kronolith if…
- Released under the GPL-2.0 license
- Written in PHP
- Tiny footprint — runs in 256 MB RAM
Frequently asked questions
Is OpenCalendar Sync or Horde Kronolith better?
OpenCalendar Sync is the stronger all-round pick: it has both the larger community and the simpler medium setup. Consider Horde Kronolith if its specific feature set fits your needs better.
Are OpenCalendar Sync and Horde Kronolith free and open-source?
Yes. OpenCalendar Sync is licensed under MIT and Horde Kronolith under GPL-2.0. Both can be self-hosted at no software cost.
Can I run OpenCalendar Sync and Horde Kronolith with Docker?
OpenCalendar Sync: yes. Horde Kronolith: check the project docs for container support.