The EPSG geodetic parameter dataset is a freely available structured repository of data used in geospatial applications. This dataset is of critical importance to the Apache Spatial Information System (SIS) project. The distribution terms have some conditions for which I would like advices. But before, some context:
- EPSG is only data, no software.
- The EPSG database is maintained by the "International Association of Oil & Gas Producers" (OGP) and members are big companies like Shell.
- Oil & Gas producers maintain and provide the EPSG database free of charge because the cost of installing a drilling platform in the wrong location is too high. Since they rely on maps and data produced by various actors (national map agencies, etc.), it is in their best interest that those actors have access to the most accurate Map Projection definitions when they create their data.
- The EPSG database, or something equivalent, is critical to a Spatial Information System. Apache SIS without EPSG would probably lost a lot of its interest. For example EPSG codes are the the-facto standard in most Web Map Services.
- I'm not aware of any freely available alternative to the EPSG database, and it would be impossible for us to create one.
- Open source and commercial products like Proj.4 (MIT license), PostGIS, GDAL, MapServer, Geoserver (GPL license), ESRI, Oracle Spatial and many other all include the EPSG database (or a subset of it) in derived forms. I think that basically all major GIS products around the world include the EPSG database in one form or the other.
The Term of Uses are there:
We can read "The EPSG Facilities are published by OGP at no charge. Distribution for profit is forbidden" followed by "The data may be included in any commercial package provided that any commerciality is based on value added by the provider and not on a value ascribed to the EPSG Dataset which is made available at no charge". My interpretation is that anyone is allowed to distribute Apache SIS + EPSG for profit, but would not be allowed to extract the EPSG tables from Apache SIS and sell only them, without anything else. In other words, the restriction would not apply on Apache SIS but emerge on what is remaining after one deleted everything from Apache. Indeed, I have never hear about any legal dispute regarding other open source projects that distribute EPSG data for years.
We can read "Ownership of the EPSG Dataset by OGP must be acknowledged in any publication or transmission (by whatever means) thereof (including permitted modifications)". Is it something that we can handle in the NOTICE file?
So would Apache SIS be allowed to bundle the EPSG database in its distribution, with a restriction that emerge only if the user delete all Apache work, and with a restriction to the changes that are allowed in the database? If the later point is problematic, would if be an acceptable workaround to use a mechanism that verify the database integrity (e.g. using a checksum) and automatically rename "EPSG" in something else if a change is detected?