Jeg har ikke drevet så mye med Wordpress-temaer selv, men det lille jeg har sett tyder på at alle Wordpress-temaer per definisjon er GPL. Det er mulig jeg tar feil, så jeg tar gjerne imot kommentarer. Dette er en oppfølging til mitt tidligere innlegg om GPL.

Wordpress er GPL, ergo temaer er GPL

Wordpress(.org) er GPL. Det er det ingen tvil om. Dersom man tar en nærmere titt på GPL vil man se at Wordpress-temaer også må være GPL:

If I add a module to a GPL-covered program, do I have to use the GPL as the license for my module?

The GPL says that the whole combined program has to be released under the GPL. So your module has to be available for use under the GPL.

But you can give additional permission for the use of your code. You can, if you wish, release your program under a license which is more lax than the GPL but compatible with the GPL. The license list page gives a partial list of GPL-compatible licenses.

Temaer kan vel heller ses på som en slags plug-in. Da gjelder følgende betingelser:

If a program released under the GPL uses plug-ins, what are the requirements for the licenses of a plug-in?

It depends on how the program invokes its plug-ins. If the program uses fork and exec to invoke plug-ins, then the plug-ins are separate programs, so the license for the main program makes no requirements for them.

If the program dynamically links plug-ins, and they make function calls to each other and share data structures, we believe they form a single program, which must be treated as an extension of both the main program and the plug-ins. This means the plug-ins must be released under the GPL or a GPL-compatible free software license, and that the terms of the GPL must be followed when those plug-ins are distributed.

If the program dynamically links plug-ins, but the communication between them is limited to invoking the `main’ function of the plug-in with some options and waiting for it to return, that is a borderline case.

Det finnes kanskje unntak, men de aller fleste temaer bruker funksjoner i Wordpress i utstrakt grad. Jeg mener at du med andre ord ikke kan lisensiere temaer under annet enn GPL-kompatible lisenser, og det er flere som er enige med meg i.

Hva innebærer dette?

Du kan fortsatt ta deg betalt for å distribuere temaene:

Does the GPL allow me to charge a fee for downloading the program from my site?

Yes. You can charge any fee you wish for distributing a copy of the program.

Men du kan ikke nekte andre, som «kjøper» temaet å legge det ut for gratis nedlasting i etterkant:

Does the GPL allow me to distribute copies under a nondisclosure agreement?

No. The GPL says that anyone who receives a copy from you has the right to redistribute copies, modified or not. You are not allowed to distribute the work on any more restrictive basis.

If I use a piece of software that has been obtained under the GNU GPL, am I allowed to modify the original code into a new program, then distribute and sell that new program commercially?

You are allowed to sell copies of the modified program commercially, but only under the terms of the GNU GPL. Thus, for instance, you must make the source code available to the users of the program as described in the GPL, and they must be allowed to redistribute and modify it as described in the GPL.

These requirements are the condition for including the GPL-covered code you received in a program of your own.

Jeg har ikke tenkt å gjør dette selv, men det kan jo være en tankevekker til de som måtte ønske å kjøpe premium-temaer til Wordpress.