We are planning to start working on a new Application (web based application) that requires us to use Geo Data.

OpenStreetMap is a free and open source data source that we could use as a starting point.

However it doesn't have everything that we need so what we are planning to do is to use their data to render the basic graphics (such as roads, parks, etc) and have a separate database to store more meta data for each geo data point.

My questions is whether if we have to make our metadata public or not ?

This is the few Urls that I found related to licensing:



Thanks in advance

  • 1
  • @mkennedy: That's a different question, about whether the application code must be opened. This question is about data added to or combined with OSM data.
    – sleske
    Dec 29, 2015 at 15:24
  • @mkennedy: I think that the link provided, and the concern regarding the added data being considered to be a derivative database is spot on. It is not a different question at all.
    – A Feldman
    Dec 29, 2015 at 15:51

2 Answers 2


This is addressed in OpenStreetMap's Legal FAQ, and, as usual, it depends.

3d. If I use your data together with someone else's data, do I have to apply your license to their data too?

If the two datasets are independent, no, you don't; this is a Collective Database.

If you adapt them to work together (for example, by taking footpaths from the OSM data, roads from the third-party data, and connecting them for routing), this is a Derivative Database and so you must (as per 3b). However, if the two datasets are matched "trivially" by, for example, automated matching using a simple criterion such as name/locality, this is not "substantial" and remains a Collective Database. There is a Community Guideline on what constitutes a trivial transformation.

OpenStreetMap Legal FAQ, question 3.4 3d

So it depends on whether your data and the OSM data are "independent", and whether your changes to the OSM data itself qualify as a "trivial transformation". This distinction is a bit vague, and is based a similar notion in the EU Database Directive. I don't think you'll find much more specific general guidance - if you need more assurance, you'll have to work with a lawyer.

In your case, if your metadata is stored separately from the OSM data (ideally, technically separated, as in a different DB table or different file), I would think it would be considered "independent". The only link between OSM data and your data would be the reference to the OSM object in the metadata (probably by coordinate or OSM ID) - that should fall under _"trivial matching" as explained above.

Thus you create a "Collective Database" and not a "Derivative Database", and the OSM license probably does not apply to your data.

  • Where I come from its called "malpractice" to advise someone to "go ahead" with something that arguably violates the license without contacting the license holder to make sure that the use will not draw a lawsuit. Ideally, get an in writing permission for the doubtful use.
    – A Feldman
    Dec 29, 2015 at 15:12
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    @AFeldman: That's why there is a General disclaimer for the site, and why I wrote "I would think" and "probably". Answers here (as anywhere on the internet) must not be taken as gospel - any internet user (hopefully) knows that.
    – sleske
    Dec 29, 2015 at 15:21
  • Of course, if you there is a concrete problem with my answer, I'll be happy to (try to) correct it.
    – sleske
    Dec 29, 2015 at 15:23

As with most "open source" projects, if you use their code then if you "distribute" with your own modifications, you have to do so under the same open source license as to your modifications as well. Your meta data arguably falls under that under this license as modified code.

So yes, you would have to make your meta data publicly available once your system goes live, as well as attribute to OpenStreetMap.

There are some exceptions to that under this license, but to make sure you don't commit your resources, only to find out that you are threatened with suit, find an attorney who also programs, ask for a written opinion on the subject code\license, and if you get a positive written opinion, even then seek out the owner of the license and get an in writing assent if possible.

As per @mkennedy's above comment and link to Legal standpoint of using open source map data in proprietary software? there is a real concern that the added data will be considered to be a derivative database.

  • No, it's not quite that simple. The ODbL (like e.g. the GPL) distinguish between "derivation" and "aggregation"/"collective database". In an aggregation, the share-alike clause does not apply to the added data.
    – sleske
    Dec 29, 2015 at 8:12
  • Also, it's arguable whether this applies to "most open source projects" - it only applies to projects under a "copyleft" or "share-alike" license. There are many popular OS licenses without copyleft, such as the MIT, BSD and Apache licenses.
    – sleske
    Dec 29, 2015 at 8:15
  • I cannot help if you didn't like my answer. Often that's the reaction I get to "bad news". Call OpenStreetMap and ask them if you like, and then you will see.
    – A Feldman
    Dec 29, 2015 at 14:54
  • It's not that I don't like your answer - I listed a few points where I believe it is misleading. Anyway, the edit improves it - thanks.
    – sleske
    Dec 29, 2015 at 15:28

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