calcurse 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?
FeaturecalcurseHorde Kronolith
Deploy effortRead-the-docs projectRead-the-docs project
Health score77 · Good69 · Good
CategoryCalendar & ContactsCalendar & Contacts
LicenseBSD-2-ClauseGPL-2.0
LanguageCPHP
Setup difficultyEasyHard
Min. RAM16 MB256 MB
Deploymentbinary, sourcebare-metal
GitHub stars★ 1,303★ 10
First released20042003
ReplacesGoogle CalendarGoogle Calendar, Exchange

What are calcurse and Horde Kronolith?

calcurse

calcurse is a text-based personal organizer with a calendar, an appointments list, and a to-do manager, all in a curses interface. It supports CalDAV synchronization so it can connect to self-hosted calendar servers.

  • Text-based calendar and to-do
  • CalDAV synchronization
  • Very low resource use

Horde Kronolith

Kronolith is the calendar component of the Horde groupware framework. It provides shared calendars, event management, and supports CalDAV synchronization with desktop and mobile clients.

  • Part of Horde groupware
  • Shared calendar support
  • CalDAV synchronization

calcurse vs Horde Kronolith: key differences

Calcurse is written in C, while Horde Kronolith is built with PHP. Licensing differs — BSD-2-Clause for calcurse versus GPL-2.0 for Horde Kronolith. Calcurse is the lighter option, starting around 16 MB of RAM against 256 MB for Horde Kronolith. Calcurse has the considerably larger community, at 1,303 GitHub stars versus 10.

Why pick each one

Choose calcurse if…

  • Released under the BSD-2-Clause license
  • Easy to set up — beginner-friendly
  • Active community (1.3k GitHub stars)
  • Written in C
calcurse details

Choose Horde Kronolith if…

  • Released under the GPL-2.0 license
  • Written in PHP
  • Tiny footprint — runs in 256 MB RAM
Horde Kronolith details

Frequently asked questions

Is calcurse or Horde Kronolith better?

calcurse is the stronger all-round pick: it has both the larger community and the simpler easy setup. Consider Horde Kronolith if its specific feature set fits your needs better.

Are calcurse and Horde Kronolith free and open-source?

Yes. calcurse is licensed under BSD-2-Clause and Horde Kronolith under GPL-2.0. Both can be self-hosted at no software cost.

Can I run calcurse and Horde Kronolith with Docker?

calcurse: check the project docs for container support. Horde Kronolith: check the project docs for container support.

Which is lighter on resources, calcurse or Horde Kronolith?

calcurse has the smaller minimum footprint at 16 MB of RAM, compared to about 256 MB for Horde Kronolith. Real-world usage depends on library size, user count, and enabled features.

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