Licenses of the landscape solutions
Goal: clarify the licenses of the open source solutions listed in order to quickly identify their limits (commercial use, SaaS, redistribution, copyleft) and their possibilities. A
Licensecolumn is present in the tables of the catalogs 01 to 05; this page provides the key for reading it.
Why look at the license?
Not all “open source” solutions offer the same rights. The license determines whether you can: use it in production, modify it, redistribute it, offer it as a hosted service (SaaS), or whether you must publish your modifications. Some recent licenses, known as “source-available”, are not validated by the Open Source Initiative (OSI) and impose restrictions (often anti-SaaS).
The main families
1. Permissive (OSI)
MIT, Apache-2.0, BSD-2/3-Clause, ISC, MPL-2.0, EUPL-1.2, PostgreSQL License
- Possibilities: free use (including commercial and SaaS), modification, redistribution, integration into proprietary software.
- Limits: attribution required; Apache-2.0 adds a patent clause; MPL-2.0 is a “weak” copyleft (file by file).
- Ideal for: frictionless adoption, integration into any type of product.
2. Copyleft (OSI)
GPL-2.0/3.0, LGPL, AGPL-3.0, EUPL (compatible copyleft)
- Possibilities: free use and modification.
- Limits: any redistribution of a modified version must be published under the same license (“share-alike”). AGPL extends this obligation to the network: if you expose the software as a service, you must publish your modifications. LGPL is more flexible (dynamic linking allowed without contaminating your code).
- Ideal for: projects wanting to guarantee that improvements remain open.
- Caution: AGPL may be incompatible with certain corporate policies.
3. Source-available (non-OSI)
SSPL, BSL-1.1 (Business Source License), Elastic License 2.0, FSL, RCL, TSL, Sustainable Use License
- Possibilities: code visible, often usable for free for most internal uses.
- Limits: commercial restrictions, generally anti-SaaS (prohibition on offering the product as a competing service). BSL/FSL often become open source (Apache/MPL) after a delay (2 to 4 years). These are not OSI licenses: to be validated with your legal team before adoption.
- Ideal for: vendors protecting their cloud model while opening the code.
4. Undeclared
No license file in the repository. Legally, “all rights reserved” by default, even if the project is public. To be clarified with the vendor before any use.
Quick decision guide
| Your need | Recommended families | To avoid / verify |
|---|---|---|
| Integrate into a proprietary product | MIT, Apache-2.0, BSD, ISC | AGPL, GPL, source-available |
| Offer a SaaS based on it | Permissive, (A)GPL if you publish | SSPL, BSL, Elastic, FSL |
| Contribute without sharing constraints | MIT, Apache-2.0 | AGPL |
| Guarantee the openness of forks | GPL, AGPL | Permissive |
| Low legal risk tolerance | OSI only | Any “source-available” / undeclared |
Landscape solutions with a non-permissive license
To watch: these solutions are included for completeness, but their license imposes constraints. Indicative list (the
Licensecolumn of the catalogs is authoritative).
Source-available (non-OSI) — legal review recommended
- SSPL-1.0: Graylog (01).
- BSL / BUSL-1.1: EMQX (01), Materialize (03), Redpanda (03), Pathway (03), SDV (05).
- Elastic License 2.0: Airbyte (01), Logstash (01), Kibana (04), Rudderstack (01), AmphiETL (03). (Major tools: note that these are not OSI licenses.)
- FSL-1.1: Chartbrew (04). fair-code / Sustainable Use: n8n (05).
- Proprietary (no SPDX): Zapier Platform (05).
Network copyleft (AGPL-3.0) — incompatible with certain SaaS policies
MinIO (02), Grafana (04), Metabase (04), Plausible (04), Grafana Loki (01), Garage (02), PeerDB (01), CKAN (05), Windmill (05), Permify (05), TDengine (03), OpenReplay (04), Rybbit (04), ToolJet (04), WrenAI (04), Green Analysis Tools (05).
Strong copyleft (GPL-2.0/3.0) — share-alike redistribution
Matomo (04), KNIME (04), Orange (04), DataEase (04), Budibase (04), Open Web Analytics (04, GPL-2.0), rsyslog (01, GPL-3.0), syslog-ng (01, GPL-2.0).
Weak copyleft (LGPL / MPL) — more flexible use
Ceph (02, LGPL-2.1); RabbitMQ / Vector / CloudQuery (01, MPL-2.0).
Undeclared license
- Odyssée (03) — ADULLACT/DGFiP GitLab repository without a license file at the time of addition. To be clarified (ADULLACT projects generally fall under free licenses such as EUPL/CeCILL, but this is not formalized here).
Automatic update
The License column of catalogs 01–05 is filled in automatically by the script
.github/scripts/update_tools_inventory.py
from the license.spdx_id field of the GitHub API (value N/A if undeclared or
unrecognized). Repositories outside GitHub (e.g. Odyssée on GitLab) are not refreshed
automatically and are filled in manually.