[mythtv] Plugins license

[Josh Lefler]

Josh Lefler
Lefler, Inc.
Phone: 314-754-8719
Toll-Free: 877-242-8558
Website: www.leflerinc.com



Colin Guthrie wrote:
> Josh Lefler wrote:
>   
>> Ivan, IANAL, but MythTV itself is released under the GPL. Since it isn't
>> possible to use GPLed code in a project that is not GPL. releasing a
>> plugin under another license would at least require reimplementing large
>> parts of MythTV that plugins depend on and at worst be impossible
>> without rewriting MythTV itself.
>>     
>
> While IAANAL, that is not my understanding of the GPL. I thought that
> you it is perfectly OK to *use* GPL'ed code in other projects, provided
> that any *modification* you make to that code are also released under
> the GPL.
>
>   
I must respectfully disagree. I believe the licensing concept you are 
describing is that of the LGPL. From 
http://www.gnu.org/licenses/gpl-faq.html#GPLInProprietarySystem

" You cannot incorporate GPL-covered software in a proprietary system. 
The goal of the GPL is to grant everyone the freedom to copy, 
redistribute, understand, and modify a program. If you could incorporate 
GPL-covered software into a non-free system, it would have the effect of 
making the GPL-covered software non-free too.

A system incorporating a GPL-covered program is an extended version of 
that program. The GPL says that any extended version of the program must 
be released under the GPL if it is released at all. This is for two 
reasons: to make sure that users who get the software get the freedom 
they should have, and to encourage people to give back improvements that 
they make."

> In the case of writing and distributing a plugin, as I understand it at
> least, it would be perfectly OK to use whichever license the user wants
> on that particular bit of code.
>
> As far as any changed the plugin required in the core mythtv, it is
> unlikely that:
> a) Ivan will *need* to modify mythtv anyway
> b) Ivan would *want* to modify mythtv *without* releasing his changes
> under the GPL.
>
> Either way that sounds OK to me.
>
>   
Even if he doesn't change MythTV, his plugin would still contain the 
binary representation of certain components of mythtv that linked in at 
compile-time. In this way, he'd be mixing free and non-free software.
>> For example. plugins must link to certain mythTV components to receive
>> input notifications, to use Myth's database utilities, etc. If your
>> component is not GPL, it would have to reimplement each of these
>> libraries independently. It wouldn't so much be a plugin as a separate
>> program that happens to be called from a menu item.
>>     
>
> While I cannot be bothered to look for examples, I am sure there are
> hundreds of applications that link against and use GPL libraries in
> commercial applications. Like I say I think it's perfectly OK to use
> GPL'ed code/libs in your (alternatively licensed) applications provided
> that any specific changes you made to GPL'ed code were made available
> under the GPL license (even if they would be effectively useless to
> anyone due to their specific tailoring to your commercial app's needs)
>   
Thats the purpose of the LGPL - to allow closed-source products to use 
open-sourced libraries. However, the GPL and the LGPL are very different 
beasts.
>   
>> May I ask what license you are considering using?
>>     
>
> I am also as curious as a dead feline. :)
>
> Col.
>
>   
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