Thunderbird Appointment vs khal

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?
FeatureThunderbird Appointmentkhal
CategoryCalendar & ContactsCalendar & Contacts
LicenseMPL-2.0MIT
LanguagePythonPython
Setup difficultyMediumMedium
Min. RAM512 MB64 MB
Deploymentdocker, sourcebinary, source
GitHub stars★ 547★ 3,039
First released20232013
ReplacesCalendly, DoodleGoogle Calendar

Why pick each one

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
Thunderbird Appointment details

Choose khal if…

  • Released under the MIT license
  • Active community (3k GitHub stars)
  • Written in Python
  • Tiny footprint — runs in 64 MB RAM
khal details

Frequently asked questions

Is Thunderbird Appointment or khal better?

Neither is universally better. khal has the larger community; both share a medium setup difficulty, so the decision comes down to features and licensing.

Are Thunderbird Appointment and khal free and open-source?

Yes. Thunderbird Appointment is licensed under MPL-2.0 and khal under MIT. Both can be self-hosted at no software cost.

Can I run Thunderbird Appointment and khal with Docker?

Thunderbird Appointment: yes. khal: check the project docs for container support.

Related comparisons