Copying code (GNU/GPL licences)

[carvegio]

Hi,

I just wanted to pick some heads on this!

If we have some software or a plugin that is available through the GNU/GPL licence and the author is happy for it to be distributed/modified.

And someone else on their website has used the plugin and modified it for their purposes.

If the modified plugin is just being used on the website and not being resold, would it be an issue/problem if I copied their changes from their code? Given the changes they have are exactly what I want.

The idea of copying doesn't sit well with me. In fact, I could probably make the changes now after viewing their source code myself, but there is only really one way of doing it. The changes would mean close to verbatim coding.

Is this an issue?

I don't want to do anything that could potentially infringe copyrights. But I also don't really want to spend money on a solicitor, given this is a free website designed for non-commercial purposes i.e. helping other people with no charge for the information.

Thanks

 

[meandu229]

What license is on the modifcations really is the question. From what I know (which isnt a lot) I could take a GPL bit of code and change it and aslong as the original code still open source and under GPL I could make my modifications closed source/under a different license etc etc.
Ignore thanks for clearing me up guys
I could be very wrong though.

 

[Evilpaul]

I could be very wrong though.

As you are not the original author you cannot unilaterally change the license on the derivative work, unless the license specifically allows it. If you take a GPL project and modify it you cannot implicitly, as part of that modification, change the terms of the license the project is under. If you get agreement from the original author you could change the license, but this is a different discussion.



As far as the OP's situation goes, the original project was under GPL and someone has modified that project and distributed it (wholly or in part of the website). This allows the OP, under the GPL terms, to request the changes the website author has made to the project as the GPL terms apply to the derivative works.

 

[carvegio]

As you are not the original author you cannot unilaterally change the license on the derivative work, unless the license specifically allows it. If you take a GPL project and modify it you cannot implicitly, as part of that modification, change the terms of the license the project is under. If you get agreement from the original author you could change the license, but this is a different discussion.



As far as the OP's situation goes, the original project was under GPL and someone has modified that project and distributed it (wholly or in part of the website). This allows the OP, under the GPL terms, to request the changes the website author has made to the project as the GPL terms apply to the derivative works.

I have researched more on copyleft and it appears that I can use the code based on my reading. Is it still worth emailing the person who modified it to let them know? Or, is that more hassle than it is worth?

I am not trying to be underhanded in any way.

 

[Evilpaul]

If you want their exact modifications you could contact the person who modified the code. They have an obligation under GPL to provide either the modified source or a patch set against a specific version.

If you have enough information about the changes from what is visible on their website then you can make the modifications yourself.

It is important to note that in either case because you are using GPL code (modified or not), if this is distributed then you become liable for also providing the source (only those parts under GPL, not your whole codebase) to someone who requests it from you.

 

[carvegio]

But what happens if it is not distributed Evilpaul? And it is just sitting on my website and someone comes along and asks for the modification?

Is there still an obligation, if I am not distributing it, but it is on my website used functionally i.e. quiz scripts used for a quiz on my site.

 

[Evilpaul]

Your website is the distributed product, it requires the GPL project to provide some functionality therefore the GPL project is also being distributed by you.

You do not need a big flashing button on your website to link to the modified GPL code, but if some one asks for it you are obliged to provide it.

 

[JonJ678]

It is important to note that in either case because you are using GPL code (modified or not), if this is distributed then you become liable for also providing the source (only those parts under GPL, not your whole codebase) to someone who requests it from you.

This is only true for surprising definitions of part. It's possible to split part of a project into gpl-infected and free, but it involves dynamic linking and providing an alternative component for the free bit. I'd suggest contacting the author and asking for permission under a different license.

Or make your whole codebase gpl, as that's the clear intent of the gpl.