KOrganizer vs OpnForm
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?
KOrganizer
Calendar and scheduling component of KDE Kontact
VS
OpnForm
Beautiful open-source form builder
| Feature | KOrganizer | OpnForm |
|---|---|---|
| Category | Calendar & Contacts | Calendar & Contacts |
| License | GPL-2.0 | AGPL-3.0 |
| Language | C++ | PHP |
| Setup difficulty | Medium | Medium |
| Min. RAM | 512 MB | 512 MB |
| Deployment | binary, source | docker |
| GitHub stars | ★ 100 | ★ 3,545 |
| First released | 2000 | 2026 |
| Replaces | Outlook Calendar | — |
Why pick each one
Choose KOrganizer if…
- Released under the GPL-2.0 license
- Written in C++
- Lightweight — runs in 512 MB RAM
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
Frequently asked questions
Is KOrganizer or OpnForm better?
Neither is universally better. OpnForm has the larger community; both share a medium setup difficulty, so the decision comes down to features and licensing.
Are KOrganizer and OpnForm free and open-source?
Yes. KOrganizer is licensed under GPL-2.0 and OpnForm under AGPL-3.0. Both can be self-hosted at no software cost.
Can I run KOrganizer and OpnForm with Docker?
KOrganizer: check the project docs for container support. OpnForm: yes.