Common licence interpretations
From OpenStreetMap
There is no definitive guide to what you can and can't do with OSM data.
The interpretations expressed on this page are the opinions of their contributors, and may be disputed by some OSM mappers and copyright holders.
Derived works
One of the most contentious issues about the OpenStreetMap License is "what constitutes a derived work?". In other words: when you build upon OSM data, under what circumstances do you have to make your finished product available under the same CC-BY-SA licence?
Do I have to put an entire webpage/website under CC-By-Sa if I include an OSM map on it?
CC-By-Sa require only an identical license for things if you derive from OSM data.
If you just include a map picture, this may be a Collective Work in which case you are free to license the rest of the page under a different licence.
A legal opinion obtained by one company which wanted to use OSM maps was that the resulting web page may be a Derivative Work terpretation, and as a result they felt it safest not to use the maps.
The map image itself has to be licensed under CC-By-SA.
I created a layer on top of an OSM map. What do I have to put under your license?
You have to determine whether what you have created is a Collective Work or a Derivative work, under the terms of the OSM licence.
- If what you create is based on OSM data (for example if you create a new layer by looking at the OSM data and refering to locations on it) then it is likely you have created a derivative work.
- If you generate a merged work with OSM data and other data (such as a printed map or pdf map) where the non-OSM data can no longer be considered to be separate and independent from the OSM data, is is likely you have created a derivative work.
- If you overlay OSM data with your own data created from other sources (for example you going out there with a GPS receiver) and the layers are kept separate and independent, and the OSM layer is unchanged, then you may have created a collective work.
If you have created a derivative work, the work as a whole must be subject to the OSM licence. If you have created a collective work, then only the OSM component of the work must be subject to the OSM licence.
I extracted some OSM data and made a picture/T-shirt/did something cool with it. Do I have to put this under your license?
If you used OSM data to derive something else that cannot be considered separate and independent of the OSM data, then you have made a derivative work, and the whole of the work must be placed under the licence.
When is it derived and when does it only use OSM data?
There are gray areas which are hard to decide.
If you want to make a business model out of some usage of OSM data, we strongly advise you to obtain legal advice.
I want to use OSM data with my GPS routing/mapping/other application. Do I have licence the application under the OSM licence?
If the application is separate and independent, you do not need to licence it under the OSM licence. However, it you distribute OSM derived data with the application, that must be distributed under the OSM licence.
Is the OSM licence (CC-SA) compatible with other "free" licences?
Other licenses similar to CC-BY-SA in spirit may be incompatible in practice. The LGPL and CC-SA are likely not compatible. See the FSF FAQ at [1]. Therefore data licensed under the LGPL cannot be used in OSM. There is work in progress between CC and FSF to address licence compatibility issues. This may result in developments in this area soon.
