This means that software that implements OMT, even if written from scratch, cannot be re-used by other FOSS projects (Apache, BSD, GPL, AGPL, other software in the OpenStreetMap ecosystem, etc) without affecting the license.
Ideally for Protomaps it should be possible to re-use just one portion - like only the label layer with your own layers from other sources, or even bundle it as a JS dependency in another open source project - without affecting the license of downstream projects.
This means that software that implements OMT, even if written from scratch, cannot be re-used by other FOSS projects (Apache, BSD, GPL, AGPL, other software in the OpenStreetMap ecosystem, etc) without affecting the license.
Ideally for Protomaps it should be possible to re-use just one portion - like only the label layer with your own layers from other sources, or even bundle it as a JS dependency in another open source project - without affecting the license of downstream projects.