Claws Mail vs Open Web Calendar
A side-by-side comparison of two self-hosted apps from related categories — licensing, setup difficulty, resource needs, and what each one replaces.
Not the right match-up?
Claws Mail
Lightweight and fast GTK email client
VS
Open Web Calendar
Embed a web calendar into your own website
| Feature | Claws Mail | Open Web Calendar |
|---|---|---|
| Category | Mail Servers | File Sync & Storage |
| License | GPL-3.0 | GPL-2.0 |
| Language | C | Python |
| Setup difficulty | Easy | Easy |
| Min. RAM | 128 MB | 50 MB |
| Deployment | binary, source | bare-metal |
| GitHub stars | ★ 200 | ★ 330 |
| First released | 2001 | 2024 |
| Replaces | Microsoft Outlook | Google Agenda, Microsoft Outlook |
Why pick each one
Choose Claws Mail if…
- Released under the GPL-3.0 license
- Easy to set up — beginner-friendly
- Written in C
- Tiny footprint — runs in 128 MB RAM
Choose Open Web Calendar if…
- Released under the GPL-2.0 license
- Easy to set up — beginner-friendly
- Written in Python
- Tiny footprint — runs in 50 MB RAM
Frequently asked questions
Is Claws Mail or Open Web Calendar better?
Neither is universally better. Open Web Calendar has the larger community; both share a easy setup difficulty, so the decision comes down to features and licensing.
Are Claws Mail and Open Web Calendar free and open-source?
Yes. Claws Mail is licensed under GPL-3.0 and Open Web Calendar under GPL-2.0. Both can be self-hosted at no software cost.
Can I run Claws Mail and Open Web Calendar with Docker?
Claws Mail: check the project docs for container support. Open Web Calendar: check the project docs for container support.