# OpenPLC Runtime v4 vs Stalwart Mail Server

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

| | OpenPLC Runtime v4 | Stalwart Mail Server |
|---|---|---|
| Score | 52/100 | 79/100 ✓ |
| Rank in category | #6 of 10 in IoT | #2 of 16 in Mail Server |
| GitHub stars | 418 | 15 484 ✓ |
| Stars, last 30 days | +2 | +681 ✓ |
| Stable releases, 12 months | 10 | 31 ✓ |
| Latest release | v4.3.1 · 13 Oct 2026 | v1.0.1 · 28 Oct 2026 ✓ |
| Setup | Moderate ✓ | Moderate |
| Official Docker image | Yes | Yes |
| License | MIT | AGPL-3.0-only AND LicenseRef-SEL |
| Main language | Python | Rust |

## Which one should you pick?

Stalwart Mail Server scores 79/100 against 52/100 for OpenPLC Runtime v4, so it is the safer default.

Stalwart Mail Server ships more often: 31 stable releases in the past year, against 10 for OpenPLC Runtime v4.

Stalwart Mail Server is growing faster right now (+681 stars in 30 days).

## Details

- [OpenPLC Runtime v4](https://selfhost.directory/project/openplc-runtime) (markdown: https://selfhost.directory/project/openplc-runtime.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/openplc-runtime-vs-stalwart-mail-server