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Re: Some licensing questions regarding celestia

A week ago Mika asked two legal questions and a Debian-policy question.

I'm not sure this extensive thread has managed to answer his questions yet (or recently whether it has even been addressing them.)

Some looking around on the web revealed that Dan Ravicher, one of the pro-bono attorneys for the Free Software Foundation, has answered a question very similar to one of Mika's. You can read lots of helpful information regarding Free Software and legal issues here:


In particular, the similar question and answer are:

"Images and Sounds
by K45
How does the GPL affect non-sourcecode files that are part of an application?

Specifically, I'm concerned about the images and sounds that are included with a game I'm working on.

Does the GPL "contaminate" these other files that are included? If so, how do "source" and "binary" distribution apply to images and sounds.



The GPL may "contaminate" sound and image files if they are part of a whole work, and that work is based on a GPL licensed program.


The relevant part of the GPL reads,

'If identifiable sections ... are not derived from the Program, and can be reasonably considered independent and separate works in themselves, then this License, and its terms, do not apply to those sections when you distribute them as separate works. But when you distribute the same sections as part of a whole which is a work based on the Program, the distribution of the whole must be on the terms of this License, whose permissions for other licensees extend to the entire whole, and thus to each and every part regardless of who wrote it. ... the intent is to exercise the right to control the distribution of derivative or collective works based on the Program. In addition, mere aggregation of another work not based on the Program with the Program (or with a work based on the Program) on a volume of a storage or distribution medium does not bring the other work under the scope of this License.'

Therefore, under the GPL, if the non-source code files are "distributed as part of a whole which is a work based on the [GPL'd] program," then the whole application, including those non-source code files, must be distributed under the GPL. However, if the non-source code files are not "based on the [GPL'd] Program" and are "merely aggregated" with the GPL'd program for distribution, then those non-source code files do not have to be distributed under the GPL. This means that the issue lies in how the non-source code files are incorporated into or with the GPL'd program.

If no source code exists for parts of the work, section 3 of the GPL states that "the preferred form of the work for making modifications to it," must be distributed in order to satisfy the "source" distribution requirement. Since I have very little technical knowledge, I'm not sure exactly what is "the preferred form" for making modifications to image and sound files..."
----END PASTE----

So it seems that Mika could aggregate the other distinct files with Celestia without having a GPL issue, but then whatever copyright governed those additional files would continue to govern them and their notices would need to be preserved. Many of these copyright licenses would likely be non-free and so I don't think the entirety could end up in Debian main.

Also, I'm not sure it's been said clearly that some data that he might be worried about is unlikely to be covered by any enforceable copyright. For example, I doubt one can copyright information about the relative locations of the planets or stars. The 3D models are another story though.

Further, the JPL Image Policy doesn't look like a copyright license. It suggests that JPL may not even be the copyright holder of images that they let you download (nearly admitting to contributory infringement!) and so you would need for each image from JPL to track down its actual owner. Good luck. (Anyone for Copyright reform?!)

Mika Fischer wrote:

[Please CC me]

I'm the new maintainer of celestia which is a space simulation program.
As such it contains a lot of data, numerical data such as positions of
stars as well as 3D models and textures.

The copyright status of all this data is a real mess and we (the authors
and me) are trying to clarify it.

What I got out of the whole FDL debate is that data in Debian has to be
DFSG-free (with which I agree).

celestia is released under the terms of the GPL.

Now the questions:
1) If one includes public-domain material in a GPL work, does one have
to state what material is in the public domain?

2) Are there any GPL-compatibility issues when the data is licensed
differently from the GPL? So if an author grants the rights to copy,
modify and redistribute is it enough to basicaly say: "This software is
GPLed but file xyz is licensed according to the following statement:
Does a list like the following suffice?
Filename: xyz
Author: Name
Terms: blah...

Filename: abc

3) What rights do need to be granted for data to be included in
non-free. In particular what about the following:
JPL Image Policy

JPL images are available for use by the public free of charge. However,
by electing to download images from this web site the user agrees that
Caltech makes no warranties or representations with respect to its
ownership of copyrights for the images, does not represent others who
may claim to be owners of rights in the images, and makes no warranties
as to the quality of the images.

Commercial users (excluding journalistic uses) are required to copy the
JPL Image Release document and return a signed copy to the Caltech's
Intellectual Property Counsel, California Institute of Technology M/C
201-85, Pasadena, California 91125, who will countersign document and
return a copy to you. Copies may be faxed to (626) 577-2528. This
document will become effective when it is countersigned by Caltech.


Brian W. Carver -- http://rurnt.com/brian              ,''`.
Try a free operating system at http://www.debian.org  : :' :
Support EFF! http://www.eff.org                       `. `'
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