Cal.diy vs OpenSlides
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
OpenSlides
Presentation and assembly system for managing and projecting agenda,
| Feature | Cal.diy | OpenSlides |
|---|---|---|
| Category | Calendar & Contacts | Calendar & Contacts |
| License | MIT | MIT |
| Language | TypeScript | Shell |
| Setup difficulty | Medium | Medium |
| Min. RAM | 512 MB | 512 MB |
| Deployment | bare-metal | docker |
| GitHub stars | ★ 47,334 | ★ 629 |
| First released | 2026 | 2026 |
| Replaces | — | — |
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 OpenSlides if…
- Released under the MIT license
- First-class Docker support for quick deployment
- Written in Shell
- Lightweight — runs in 512 MB RAM
Frequently asked questions
Is Cal.diy or OpenSlides better?
Neither is universally better. Cal.diy has the larger community; both share a medium setup difficulty, so the decision comes down to features and licensing.
Are Cal.diy and OpenSlides free and open-source?
Yes. Cal.diy is licensed under MIT and OpenSlides under MIT. Both can be self-hosted at no software cost.
Can I run Cal.diy and OpenSlides with Docker?
Cal.diy: check the project docs for container support. OpenSlides: yes.