Cal.diy 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?
Cal.diy
Online appointment scheduling system
VS
Horde Kronolith
Calendar application from the Horde groupware suite
| Feature | Cal.diy | Horde Kronolith |
|---|---|---|
| Category | Calendar & Contacts | Calendar & Contacts |
| License | MIT | GPL-2.0 |
| Language | TypeScript | PHP |
| Setup difficulty | Medium | Hard |
| Min. RAM | 512 MB | 256 MB |
| Deployment | bare-metal | bare-metal |
| GitHub stars | ★ 47,334 | ★ 10 |
| First released | 2026 | 2003 |
| Replaces | — | Google Calendar, Exchange |
Why pick each one
Choose Cal.diy if…
- Released under the MIT license
- Mature project with 47.3k GitHub stars
- Written in TypeScript
- Lightweight — runs in 512 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 Cal.diy or Horde Kronolith better?
Cal.diy 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 Cal.diy and Horde Kronolith free and open-source?
Yes. Cal.diy is licensed under MIT and Horde Kronolith under GPL-2.0. Both can be self-hosted at no software cost.
Can I run Cal.diy and Horde Kronolith with Docker?
Cal.diy: check the project docs for container support. Horde Kronolith: check the project docs for container support.