Alf.io vs Thunderbird Appointment
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?
Alf.io
Ticket reservation system
VS
Thunderbird Appointment
Self-hostable scheduling tool for booking meetings
| Feature | Alf.io | Thunderbird Appointment |
|---|---|---|
| Category | Calendar & Contacts | Calendar & Contacts |
| License | GPL-3.0 | MPL-2.0 |
| Language | Java | Python |
| Setup difficulty | Medium | Medium |
| Min. RAM | 512 MB | 512 MB |
| Deployment | bare-metal | docker, source |
| GitHub stars | ★ 1,601 | ★ 547 |
| First released | 2025 | 2023 |
| Replaces | — | Calendly, Doodle |
Why pick each one
Choose Alf.io if…
- Released under the GPL-3.0 license
- Active community (1.6k GitHub stars)
- Written in Java
- Lightweight — runs in 512 MB RAM
Choose Thunderbird Appointment if…
- Released under the MPL-2.0 license
- First-class Docker support for quick deployment
- Written in Python
- Lightweight — runs in 512 MB RAM
Frequently asked questions
Is Alf.io or Thunderbird Appointment better?
Neither is universally better. Alf.io has the larger community; both share a medium setup difficulty, so the decision comes down to features and licensing.
Are Alf.io and Thunderbird Appointment free and open-source?
Yes. Alf.io is licensed under GPL-3.0 and Thunderbird Appointment under MPL-2.0. Both can be self-hosted at no software cost.
Can I run Alf.io and Thunderbird Appointment with Docker?
Alf.io: check the project docs for container support. Thunderbird Appointment: yes.