Hello Bertil
Le 22/11/2022 à 21:47, Bertil Chapuis a écrit :
The terms of the EPSG license are restrictive [1]: The data may not be
distributed for profit by any third party. I’m quite amazed to
discover that most geospatial solutions out there are probably
violating this license.
Yes. In the case of PROJ version 6 and later, complying to the license
would be just a matter of releasing PROJ under MIT + EPSG terms of use,
not MIT alone. Because PROJ is used by GDAL, QGIS and PostGIS (among
others), the issue apply to all those software as well and could be
resolved in the same way. But my understanding is that adding EPSG Terms
of Use would cause problems for packaging QGIS and PostGIS in some Linux
distributions (it is a matter of license policy, like the policy we have
at Apache), which is why PROJ maintainers are reluctant to address the
issue.
For PROJ version 4, the situation is more tricky because that old
version modified the EPSG dataset, notably by changing axis order to
(longitude, latitude). The EPSG license does not allow such
modifications (because they change the numerical results of coordinate
operations), or at least not under "EPSG" namespace. So PROJ4 and PROJ4J
are more difficult to resolve. PROJ version 6 and later are better
because since version 6, PROJ respects EPSG data integrity.
[1]https://svn.osgeo.org/geotools/trunk/licenses/EPSG.html
This is an old version of EPSG terms of use. Current version is
https://epsg.org/terms-of-use.html
Compared to the old version, the new version explains in more details
what kinds of changes we are allowed to do. In brief we are allowed to
do some changes, but not any changes; they provide a table listing what
we can do. This restriction is based on a good intention: the changes
shall not alter the result of coordinate operations, otherwise (in worst
case) safety could be compromised. Other conditions worth to note are:
* (…snip…) any use of the EPSG Facilities (…snip…), even if obtained
without clicking acceptance, will be acceptance of these Terms of Use.
* You are obliged to inform anyone to whom you provide the EPSG
Facilities of these Terms of Use.
In other words, even if we obtained the EPSG data in another way than
direct download from EPSG web site (e.g. if we obtained the EPSG data
through PROJ4 CSV files), the EPSG terms of use still apply.
Concretely, does this mean that we could include a couple of EPSGs
(not the full database) without concern? In Baremaps, we mainly
require EPSG:4326 and EPSG:3857. It not yet clear to me if we can
import proj4j and exclude parts of the EPSG database.
In Apache SIS I took the risk of including a hard-coded definition of
EPSG::4326 used as a fallback if the EPSG dataset is not installed,
because that code is so widely used. I included a few other codes as
well. I hope that they fall under the "Fair Use" exception, which is
allowed by U.S. law [1]. However this is my uneducated interpretation
and I may very well be wrong.
[1]https://www.copyright.gov/help/faq/faq-fairuse.html
In the context of a cli, I would prefer to find a solution where the
user is not prompted to accept the terms of the EPSG license. For
instance, could we have a command (e.g. ./baremaps non-free) that
downloads these jars in the lib folder?
I don't know. We can ask for advice by opening a JIRA issue on
https://issues.apache.org/jira/projects/LEGAL/
For making the task easier for legal volunteers, we should not go in
details of what is EPSG. Just said that it is a widely used dataset,
that the license is classified Category X by Apache (with a link to the
license on EPSG web site) and maybe said that a similar issue was
discussed in https://issues.apache.org/jira/browse/LEGAL-183 and
resolved by prompting users (when SIS is used as an application) or
requiring developers to add themselves a Maven dependency (when SIS is
used as a library).
They may ask that EPSG data are not downloaded from an Apache server.
Preference may be let users download themselves from EPSG web site, but
I agree that it is so unconvenient (we have to open an account) that not
many users will do that. In Apache SIS case, the data are downloaded
from Maven Central.
I think the Eclipse Foundation did an exception for the locationtech
group. According to their FAQ [2] they asked the permission to
redistribute some pervasive dependencies in geospatial projects: “We
can re-distribute the binaries for certain components. We do have
explicit permission to re-distribute Geotools, JTS, and GEOS.”.
In the case of Geotools, I guess Eclipse accepted the LGPL license. JTS
was also used to have a non-compatible license, but they changed a few
years ago to a more permissive one, so the exception may not apply
anymore. I'm not sure they were aware of EPSG Terms of Use when they
granted exception.
Anyway, there is nothing wrong in distributing EPSG data in an
application, provided that we include EPSG terms in the license folder.
Whether a foundation (Apache, Eclipse, Linux distribution…) accepts EPSG
license is a matter of foundation policy. Each organization, or each
individual, can choose their own policy regarding which licenses to accept.
Martin
