Re: [Partysip-dev] Writing plug-ins and licensing

[Aymeric Moizard]

On Mon, 5 Sep 2005, Jeremy Pullicino wrote:

> Hi,
>
> I would like to write my own proprietry plug-in that will be very similar to
> the UDP plug-in except that it will perform some special logging to a custom
> databsase. This plug-in will not be useful to anyone apart from myself so I
> do not want to GPL it.
>
> I was looking at the UDP plug-in and can see that it links to the following
> libaries:
>
> partysip.lib
> ppl.lib
> osipparser2.lib
> osip2.lib
>
> Linking to GPL means I need to GPL my source code -
> http://www.gnu.org/licenses/gpl-faq.html#LinkingWithGPL
>
> The web site of partysip states this:
>
> " As the entire code of the core application is LGPL, it is allowed to build
> proprietary plugins. This is useful when you want to build specific services
> which code is useless for the general public. As an example, proprietary
> plugins can be used to manage proprietary database information that comes
> with their products." - http://www.nongnu.org/partysip/partysip.html
>
> A few important questions need to be answered:
>
> 1. Are osipparser2 and osip2 LGPL or GPL?

LGPL. You can link with closed source code.

> 2. Does the UDP plug-in need to link with them?

Yes.

> 3. Is it true that I could create my own proprietry plug-in without having
> to GPL it?

Yes, because partysip's include files are also LGPL (the core application
is still GPL).

> 4. Will writing my own plug-in require changes in the partysip code?

No. If it does, the change must be open source.

> 5. If I write and distribute my own plug-in I need to also distribute a
> custom configuration file. Is the configuration file covered by GPL?

No.

Still, if your plugin won't be usefull for others (as you said), I don't
see any reason why you wouldn't release it as GPL and open the source 
code.

People could use your plugin as a sample and users of your plugin can
patch it! For example, I would enjoy to look at your plugin.

Thanks
Aymeric

> Thanks for your help.
>
> Jeremy Pullicino