[OSM-legal-talk] Is the "data share-alike" road navigable?

[Richard Fairhurst]

Laurence Penney wrote:

> Can someone explain how this would work if I publish (print or web) an
> OSM-derived map, whereupon are overlaid data that cannot be licensed
> CC-BY-SA?
>
> For example, I put Placeopedia markers all over the map. (The
> locations are derived from Google Maps.) For another example, the
> Ordnance Survey gives me permission to show MasterMap data in a
> transparent layer on top of an OSM map.
>
> Won't almost all cool uses that will be thought of for OSM data suffer
> this way?

At the moment we have a webmap layer clarification/exemption for the  
licence. It's section 2.2 at http://wiki.openstreetmap.org/index.php/ 
Legal_FAQ . This says other layers don't have to be copylefted.

This was written by Imi (AIUI), who's quite a strong advocate of  
copyleft. No-one has voiced any opposition to it - so I'd suggest we  
retain it.

cheers
Richard