# open-web-calendar vs Stalwart Mail Server

> Two self-hosted projects, compared on the numbers selfhost.directory tracks live: score, popularity, release cadence and setup effort.

| | open-web-calendar | Stalwart Mail Server |
|---|---|---|
| Score | 53/100 | 78/100 ✓ |
| Rank in category | #9 of 30 in Calendar & Contacts | #2 of 16 in Mail Server |
| GitHub stars | 334 | 15 458 ✓ |
| Stars, last 30 days | — | +674 |
| Stable releases, 12 months | 0 | 30 ✓ |
| Latest release | — | v1.0.0 · 26 Oct 2026 |
| Setup | Moderate ✓ | Moderate |
| Official Docker image | Yes | Yes |
| License | GPL-2.0 | AGPL-3.0-only AND LicenseRef-SEL |
| Main language | Python | Rust |

## Which one should you pick?

Stalwart Mail Server scores 78/100 against 53/100 for open-web-calendar, so it is the safer default.

Stalwart Mail Server ships more often: 30 stable releases in the past year, against 0 for open-web-calendar.

Stalwart Mail Server is growing faster right now (+674 stars in 30 days).

## Details

- [open-web-calendar](https://selfhost.directory/project/open-web-calendar) (markdown: https://selfhost.directory/project/open-web-calendar.md)
- [Stalwart Mail Server](https://selfhost.directory/project/stalwart-mail-server) (markdown: https://selfhost.directory/project/stalwart-mail-server.md)

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Source: https://selfhost.directory/compare/open-web-calendar-vs-stalwart-mail-server