Re: [Nel] NeL's GPL status

[azhrarn]

On Thu, Jul 08, 2004 at 03:33:20PM -0700, Damon Trask wrote:
> Hey all, new to the list and got a quick question for you folks here.
> I am brand new to NeL, and considering using it to work on a commercial 
> game project. But I have a few questions about the GPL liscense attached to 
> the source.
> 
> A friend of mine said that GPL is interpreted that if you link, call or use 
> GPL'd code in any fashion in a piece of software intended for public 
> distribution, that you must include *all* the source code of the intended 
> software, even if the GPL parts are very small/minor.
> Is this true?

For linking or calling, generally it is true for GPL.  Which is why it
is typically termed as a "viral" license.  Although that has some
negative connotations. ;)  But "use" is vague.

The following entries in the GPL FAQ may be of help:

http://www.gnu.org/licenses/gpl-faq.html#MereAggregation
http://www.gnu.org/licenses/gpl-faq.html#GPLInProprietarySystem
http://www.gnu.org/licenses/gpl-faq.html#LinkingWithGPL

I believe you can contact address@hidden if you have any specific
questions as well.

Essentially, if the code is in the same executable, or even a shared
library (they call into each other etc), it all has to be GPL.  The only
real way to keep them seperate is by chaining together seperate
executables with some high level IPC apparently.  Or you can (for
example), have your login/patch interface be a seperate program then
your actual game client.  Although I'm sure making revolutionary
proprietary developments in game launcher technology isn't exactly your
main focus.

They go on to say that this type of behavior is intended, as mixing GPL
and non-GPL causes all sorts of ambiguity with the users and such as they
determine what they can and can't modify etc.  GPL is one of the more
heavy handed licenses (BSD and Artistic are known to be a bit more
friendly to third parties), and intentionally so.

Technically, the developer can make an exception and dual license the
code.  Which lets them release closed modifications for their own
purposes etc.  So, you may be able to get Nevrax to grant you an
exception, although you would of course have to work that out on your
own. ;)  However, I am not sure of the legal issues of other people
contributing code to NeL with the understanding that it was GPL.  As
there may be code copyrighted to third parties commited to the NeL
codebase as GPL, which would mean they would need to authorize any
license split as well.

http://www.gnu.org/licenses/gpl-faq.html#ReleaseUnderGPLAndNF
http://www.gnu.org/licenses/gpl-faq.html#Consider

> Also, if this *is* true, how would it be possible to design a commercial 
> Persistant State World game client under GPL (meaning the source becomes 
> public), and still maintain system/service security.
> If the source to the client becomes public, is it still possible to keep 
> people from hacking, cheating, or any number of malicious activities 
> against your product/service?
> 
> Any help here would be appreciated...

As far as security, keep in mind that packet
injection/sniffing/rewriting is rampant in every game already, whether
or not people have access to the client internals (also see "Security
through Obscurity" and possibly "Kerckhoffs' Principle").  Of course,
you hinted at only using a small part, but otherwise, I would imagine
the bulk of the intellectual property in any game client would be the
content of the game world - which would be server side.  Including AI,
etc.  The other main features would be the art itself, which would be
client side and still copyrighted to you of course.

I'm not really sure of any other security issues outside of the cheating
that is already possible with existing games (anywhere from Diablo2
closed realm dupe hacks, to Everquest speed hacks, to UO player run shards...)
that open source would exascerbate.  There's also the legal route, where
you can require users to play nice or you cancel their account at best,
and take legal action at worst.

Hope that helped a bit. ;)