Licensing implications when extending POI with external metadata


I’m planning to develop an Android application that displays OpenStreetMap POIs near you and complements the OSM data with data coming from other sources (address, phone numbers, user notes, etc.).
What are the license implications in doing that? Would I have to expose the combined data under the ODbL? Would that be considered “derivative work” even if I don’t change the OSM data or keep the two databases “physically” apart and use only references?

Please advise.


I posted these same questions to the legal mailing list and people called to my attention that the current license i not ODbL but CC-BY-SA 2.0. In case you are wondering why I’m doing this “double posting”: I would like to get answers from the legal mailing list, but I also think it’s relevant that the general OSM community discusses these type of issues in a broader forum and understands the implications of the current licensing schema.

Here is my follow up email to the legal mailing list:

I apologize for the mistake. Not the best way to start posting in this forum. I’m actually aware that the current license is CC-BY-SA 2.0 and this was an unfortunate copy/pas mistake.

I do believe that my original questions still stand, as both licenses have a “share-alike” requirement. Of all the license requirements, that’s the one that concerns me most, as providing all of my business data under the CC-BY-SA 2.0 would not be viable. Here are some of the questions that pop to mind:

  • If a commercial application complements OSM POI data with user-provided data (example: display a OSM POI along with user-provided address, phone number, etc.), is that considered “altering, transforming, or building upon” OSM data? In that example, would I have to distribute my user-provided data under the CC-BY-SA 2.0 license?
  • What if I keep the OSM POI data in a separate database and only reference it, would that make a difference?
  • If I help the community by feeding some of my user-provided data back to OSM, would that make a difference?
    If the OSM POI data is displayed together (i.e. in the same page or same screen or same map, etc.) with data and POIs from other sources, does the “share-alike” apply?


Let’s start with this. According to the opinion held by a majority of OSM’s contributors, merely displaying data together with OSM-based works on the same screen is not a problem in any way. Solutions that let the client combine different data sources (such as layers in slippy map websites) are already widely used to use OSM-based maps together with data/maps under incompatible licenses. The planned license change will explicitly allow such usage even on printed maps.

I’m not sure whether I read the example correctly. Let’s break this down:

  • Whether data is displayed together with OSM data doesn’t matter, see above.
  • Whether your application is commercial/for-profit doesn’t matter either.
  • If your users create data based on something else than OSM - say, notes attached to a GPS position -, then OSM’s share alike doesn’t apply, even if the note then shows up on top of an OSM map.
  • If data is never published but only used by the user/organization who created it, then the share alike doesn’t apply, even if said data was derived from OSM.

If, however, your users essentially select OSM objects, add “attributes” to to them, provide the additions to you, and you publish the collected results, then the share alike most likely applies.

It should be possible to use both OSM data and independent data sources in an application without producing a database derived from OSM. This is irrelevant, however, if data is actually created based on OSM and only separated later on.

I guess that many would be personally happy with your use of the data if you contributed back to OSM, but legally, this doesn’t really matter.

Under ODbL, you will be required to license as an ODbL database all data that was created based on OSM data and published by you. If you only publish some of the data, or only some of it is derived from OSM, then licensing that part as ODbL would be enough, of course.