[OSM-legal-talk] using osm data and other sources in a project

Robert Whittaker (OSM) robert.whittaker+osm at gmail.com
Thu Aug 18 16:34:59 BST 2011

On 9 August 2011 03:17, maning sambale <emmanuel.sambale at gmail.com> wrote:
> I have a mapping project for an organization involved in conservation
> and natural resources management.  We are planning to create an
> internal/local webmapping application to help the organization in
> monitoring several projects in an area.  We would like to to use a
> subset of OSM data and mix the org's internal data in the application.
> We will download the osm data and create our own tiles/wms.  For the
> roads, we will update the attributes for additional info the org needs
> (i.e. admin types, etc).  For the river, we will also update
> attributes (i. e. stream orders, etc.).  We plan to add the additional
> geometry to OSM whenever there are improvements, but I don't think the
> other specific attributes are needed by OSM.  For the other internal
> data, this will be on a separate db/layer but will probably be
> integrated into the osm layers for simple map-based monitoring
> reports.
> Is this a legal use case of OSM data? Specifically,
> 1.  Is it OK not adding back to the main OSM db the modified
> attributes of the OSM layers?
> 2.  Where should we include attribution requirements? (in the webmap
> ala openlayers attribution js, in all map reports, etc.)
> 3.  What about the use of WMS/Tiles combining both osm and other
> internal datasets?

My understanding of ODbL is the following:

* There's no requirement to contribute any data back to OSM directly,
but there may be a requirement to provide some data to people who ask
for it. (That's the "share-alike" aspect of the license.) People who
request the data from you may then be able to add it back to OSM

* If your use of the OSM data is internal to your organisation, I
think that you don't need to worry about any of the attribution or
share-alike provisions.

* If you publish any data based on a database that's derived from OSM
data, then you need to publish that data under the ODbL license (or a
compatible one).

* If you publish any map tiles that were produced using data from a
database that was derived from OSM, then this is a "Produced Work"
under ODbL. You can release them under any license (from public domain
to all rights reserved) so you can restrict what people can do with
the images as much or as little as you like. However, you must provide
attribution as specified in 4.3 of the ODbL and also either:
(a) Provide that database used to generate the tiles under the ODbL
license (or a compatible one) to anyone who asks for it, or
(b) Provide details of the modifications / extraction method used to
create the database from the OSM data, including any additional data
that you added.
So publishing map tiles based on a combined OSM + external data
database would mean you would have to release the external data you

* The only way round this is not to combine the OSM data with your
additional data in the same database, but to keep the two data-sets
entirely separate (which means you can't filter one based on the
other, or use one to change attributes in the other). You can then
create two tile layers, one from each database, and then display them
on top of each other to achieve the desired result. Only the OSM set
of tiles comes under the ODbL rules, and so you only have to release
the OSM database (or a description of how you obtained it).

* I think it's an open question as to whether it's permissible to
create a single layer of tiles from the two databases by overlaying
features from both. It could be argued that this is a collective work,
rather than a single produced work.

Hope that helps,


Robert Whittaker

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