# Licensing

BSF Project uses a **tri-license** layout. One permissive software license for the web app does not correctly cover tank hardware or educational writing, so each tree has its own terms.

| Tree | License | SPDX | Full text |
|------|---------|------|-----------|
| Web app & tooling | MIT | `MIT` | [`licenses/MIT.txt`](licenses/MIT.txt) |
| Digestion tank designs | CERN Open Hardware Licence Version 2 – Permissive | `CERN-OHL-P-2.0` | [`licenses/CERN-OHL-P-2.0.txt`](licenses/CERN-OHL-P-2.0.txt) |
| Guides & most media | Creative Commons Attribution 4.0 International | `CC-BY-4.0` | [`licenses/CC-BY-4.0.txt`](licenses/CC-BY-4.0.txt) |

## What applies where

### MIT — web app

Applies to:

- `src/`
- `index.html`, `sw.js`, `manifest.webmanifest`
- `test/`, `scripts/`, `package.json`, `package-lock.json`, `c8.config.json`
- `data/` (machine-readable schemas and related tooling files)

You may use, modify, and redistribute this software, including commercially, with copyright and license notice retained. Hosted member portals, AI backends, and private infrastructure outside this repository remain separate and are not licensed here.

### CERN-OHL-P-2.0 — open hardware designs

Applies to:

- `designs/` (CAD, BOMs, design-specific build docs under each design’s `docs/`, design images)

CERN-OHL-P is written for hardware. Anyone may use, study, modify, share, and manufacture these designs—including commercially—under the licence terms (keep notices and attribution as required). We intentionally use the **permissive** variant so chapter and manufacturing partners can produce tanks without a copyleft hardware obligation.

Avoid “Non-Commercial only” hardware licences here: they conflict with open-source hardware norms and with partners who need to sell fabricated systems locally.

### CC BY 4.0 — guides and shared media

Applies to:

- `guides/`
- `articles/` (in-depth topic pages and catalog prose)
- `communities/` (registered local project pages and registry prose)
- `assets/` (photos, diagrams, and other media we publish here), except as noted below
- First-party prose we author under `resources/` (indexes, summaries). Third-party works stay under their own terms—see `resources/ATTRIBUTION.md`.

You may copy, translate, remix, and commercially redistribute this material if you give appropriate credit.

**Trademarks:** The names “BSF Project”, “bsfproject.com”, and logos are not licensed for use in a way that implies endorsement or creates brand confusion. Attribution under CC BY does not grant trademark rights.

## Design-specific docs vs guides

- Build/assembly docs that ship with a tank design → **CERN-OHL-P-2.0** (`designs/<name>/docs/`)
- Cross-cutting biology, operations, and troubleshooting → **CC BY 4.0** (`guides/`)

## Contributions

Unless you state otherwise in the PR, contributions are offered under the license of the tree you modify (MIT, CERN-OHL-P-2.0, or CC BY 4.0). See `CONTRIBUTING.md`.