Horde Groupware vs Kolab Groupware
A side-by-side comparison of two self-hosted groupware options — licensing, setup difficulty, resource needs, and what each one replaces.
| Feature | Horde Groupware | Kolab Groupware |
|---|---|---|
| Deploy effort | Read-the-docs project | Under-an-hour setup |
| Status | Archived | Actively maintained |
| Category | Groupware | Groupware |
| License | GPL-2.0 | AGPL-3.0 |
| Language | PHP | PHP |
| Setup difficulty | Hard | Hard |
| Min. RAM | 512 MB | 2,048 MB |
| Deployment | bare-metal, source | bare-metal, docker |
| GitHub stars | ★ 242 | ★ 200 |
| First released | 2003 | 2002 |
| Replaces | Microsoft Exchange | Microsoft Exchange, Zimbra |
What are Horde Groupware and Kolab Groupware?
Horde Groupware
Horde Groupware is a collaboration suite built on the Horde framework that combines webmail, calendar, address book, tasks, and notes. It is a long-running PHP groupware project for teams.
- Webmail with calendar
- Shared address books
- Tasks and notes
- Modular Horde framework
Kolab Groupware
Kolab is an open-source groupware solution providing email, shared calendars, contacts, tasks, and notes. It integrates standard components like Postfix, Cyrus IMAP, and Roundcube into a coherent collaboration platform.
- Email and calendaring
- Shared address books
- ActiveSync support
- Standards based
Horde Groupware vs Kolab Groupware: key differences
The biggest difference is maintenance: Horde Groupware's repository is archived and no longer developed, while Kolab Groupware is actively maintained. Both projects are written in PHP. Licensing differs — GPL-2.0 for Horde Groupware versus AGPL-3.0 for Kolab Groupware. Horde Groupware is the lighter option, starting around 512 MB of RAM against 2,048 MB for Kolab Groupware. Kolab Groupware lists first-class Docker deployment; Horde Groupware does not.
Why pick each one
Choose Horde Groupware if…
- Released under the GPL-2.0 license
- Written in PHP
- Lightweight — runs in 512 MB RAM
Choose Kolab Groupware if…
- Built on proven components
- Strong standards support
Watch out for
- Complex to install
- Steep operational curve
Frequently asked questions
Is Horde Groupware or Kolab Groupware better?
Neither is universally better. Horde Groupware has the larger community; both share a hard setup difficulty, so the decision comes down to features and licensing.
Are Horde Groupware and Kolab Groupware free and open-source?
Yes. Horde Groupware is licensed under GPL-2.0 and Kolab Groupware under AGPL-3.0. Both can be self-hosted at no software cost.
Can I run Horde Groupware and Kolab Groupware with Docker?
Horde Groupware: check the project docs for container support. Kolab Groupware: yes.
Which is lighter on resources, Horde Groupware or Kolab Groupware?
Horde Groupware has the smaller minimum footprint at 512 MB of RAM, compared to about 2,048 MB for Kolab Groupware. Real-world usage depends on library size, user count, and enabled features.