Recently there seems to have been an increase in the number of people contacting me about Stellarium being sold - on auction sites or in one case as part of a package from a "name a star" business. My stance on this is that so long as the sellers abide by the terms of the GPL license, there's little reason to get upset about it.

It's legally OK for anyone to re-distribute Stellarium and charge a reasonable fee for such distribution, provided that the terms of the GPL are met - most importantly in my eyes that sourcecode is distributed as well as binaries (including all modified source), that copyrights are not modified in any way, and that derivative works are licensed under the GPL. Sellers are also not allowed to claim or imply that Stellarium is their own work.

However, there are some things when potential sellers should keep in mind that the following are NOT OK with me personally:

• Charging a distribution fee, and then re-directing buyers to the official site for the download. If you charge a fee for distribution, you damn well better be providing download servers of your own and not leaching off sourceforge.
• You are making money from something which is freely available for download elsewhere on the Internet. Hiding this fact from your customers is deeply dishonest. If you do it, you're a lowlife. There may be a sucker born every minute - you do not have an obligation to rip them off like a total douche.
• Not linking to the Stellarium web site. You're making money from our work. At least do us the courtesy of linking to the project to improve our search ranking.

I also have a personal gripe with people using Stellarium to sell some lousy product like one of these "name a star" things, although this is matter of personal taste. A certificate is printed, and record gets added to a private database recognized by precisely no one in the wider Astronomy community. Lame.

An example of such a business using Stellarium was recently brought to my attention by a Stellarium user. I include this correspondence as an illustration. I hope it serves as an example to businesses who wish to use Stellarium and other open source programs, that getting the tone wrong might alienate a lot of potential customers.

Dear stellarium developers!

By chance I discovered today that a german enterprise is claiming more or
less that "stellarium" is their product. As I saw that "Stellarium" is
not their product but open source I was outraged about this imperdinence.

The enterprise is SpaceRegistry GmbH [ed: various company details
removed for the sake of brevity]

Websites (all the same under different names): www.sternportal.de
www.stella-registry.de

They sell the naming of stars. Part of their commercial packet (up to 230
USD!) is besides a certificate and a CD a downloadlink to "their
stellarium", hosted on their site. I found the downloadlink free by chance,
normally they sell it (getting the link after the payment). See also
http://www.stella-registry.de/stellarium/

In the different FAQs they're claiming:
* with the stellarium from SpaceRegistry you can...
* with our stellarium you can ...
* After you named the star you get a personal download-link
(exclusive link)

In my eyes they're more or less blatantly selling Stellarium for money!
Possibly the software is also on the cd they ship with their "certificate".

I thought I should bring this to your attention.

With best regards
Udo Weiler, germany

My response:

Hello Udo,

Firstly, thanks for keeping an eye out for the interests of the
Stellarium project, and taking the time to contact me. We get this
sort of thing fairly frequently, although this is a new twist on it -
usually it's people selling Stellarium on ebay to unwitting buyers who
do not know it is available for free download from the official
project site.

While this sort of thing is irritating, (especially if the seller
tries to obscure the name of the project), it may or may not be
illegal. The license Stellarium uses (the GNU GPL version 2) allows
for a fee to be charged for distribution, so long as the conditions of
the GPL are met... that the source is available on request, any
derivative works are licensed under the GPL, and the copyright notices
are not modified in any way (I mention only some of the important
conditions of the license).

It's rather difficult to tell from SpaceRegistry's website if they
break these terms, especially if they are charging for the
distribution of Stellarium as part of a wider package. Personally I
find these "name a star" businesses to be profoundly annoying, but
that's not illegal yet. In fact this particular company at least say
in their FAQ that the registration is in a private database and is not
used in scientific circles, which is clearer than some of their
rivals.

Unless you have some reason to believe they are breaching the terms of
the GPL (e.g. distributing a modified version of the program as a
binary without making the source code available), there is little more
to be done. With your permission I will post this correspondence to
my site. It would be nice to publicly associate their company name
with clarification that these sorts of businesses are selling only an
entry in their own private database. I doubt it will stop people
sending them money however... There's a sucker born every minute.

Best Regards,
Matthew Gates