Licensing
Overview
CERTH’s Open Science commitments, aligned with the European Open Science Cloud (EOSC) and Horizon Europe requirements, encourage making software developed in the course of publicly funded research available as open source wherever possible.
Licence selection should involve a consultation with the CERTH OSPO. When selecting a licence, consider:
- Community norms within your ecosystem
- Which sharing regime (permissive, weakly-reciprocal, or strongly-reciprocal) aligns with your project’s objectives (see Key concepts: Licensing)
- Obligations imposed by your funding body or consortium agreement
Licensing Software
Use a licence approved by the Open Source Initiative (OSI) for CERTH-copyrighted software. Common choices:
| Licence | Type | Typical use case |
|---|---|---|
| Apache-2.0 | Permissive | General software; maximum adoption; includes patent grant |
| MIT | Permissive | Small utilities and libraries; minimal requirements |
| GPL-3.0 | Strongly reciprocal | Tools where all derivatives must remain open source |
| LGPL-3.0 | Weakly reciprocal | Libraries intended to be linked from proprietary software |
Licence Compatibility
When combining components under different licences, compatibility must be verified before release. This is part of your due diligence (see Key concepts: Due diligence).
A common compatibility matrix:
| You want to use… | Under Apache-2.0 | Under MIT | Under GPL-3.0 |
|---|---|---|---|
| Apache-2.0 code | ✓ | ✓ | ✓ |
| MIT code | ✓ | ✓ | ✓ |
| GPL-3.0 code | Only if your project is also GPL-3.0 | Only if your project is also GPL-3.0 | ✓ |
| LGPL-3.0 library | ✓ (dynamic linking) | ✓ (dynamic linking) | ✓ |