GPL License for Plugins?

Added by harry grabner over 2 years ago

Hi!

I've searched the redmine website but i could not find the following information:
It is necessary to distribute redmine plugins under the GPL License?
Is it necessary to distribute redmine plugins at all?

thanks in advance for your answers!

harry

(I've already posted this in the open discussion Forum, but i did not get any replies.
So I decided to "cross post" this one to the Development forum.)

Replies (12)

RE: GPL License for Plugins? - Added by Maxim Nikolaevich almost 2 years ago

harry grabner wrote:

It is necessary to distribute redmine plugins under the GPL License?

As i understand GPL licence - answer is yes. Cause redmine and plugins used one space. It similar like wordpress or joomla plugins
But some guys ignore this requirements of GPL example

Is it necessary to distribute redmine plugins at all?

No. Gpl allow to develop gpl code without distribution. But since you distribute some product you should distibute them source code.

RE: GPL License for Plugins? - Added by Jan Niggemann (redmine.org team member) almost 2 years ago

harry grabner wrote:

It is necessary to distribute redmine plugins under the GPL License?

http://www.gnu.org/licenses/gpl-faq.html#GPLAndPlugins
I'd say yes.

RE: GPL License for Plugins? - Added by William Graber 12 months ago

If that's true, then what's up with plugins like http://www.redmine.org/plugins/ms-project-import ? This guy is charging 390 euros for a plugin that by all rights should be released for free. Not only that, but is advertising for it on redmine's plugin page. There are a whole suite of plugins on there relating to "EasyRedmine", all for absurd sums of money.

If the plugin architecture is released under the GPL, as Redmine is, then this guy is in violation of the license.

RE: GPL License for Plugins? - Added by William Graber 12 months ago

William Graber wrote:

If that's true, then what's up with plugins like http://www.redmine.org/plugins/ms-project-import ? This guy is charging 390 euros for a plugin that by all rights should be released for free. Not only that, but is advertising for it on redmine's plugin page. There are a whole suite of plugins on there relating to "EasyRedmine", all for absurd sums of money.

If the plugin architecture is released under the GPL, as Redmine is, then this guy is in violation of the license.

Wow, he did release it under GPL (https://www.easyredmine.com/faq):

What do I obtain buying Easy Redmine and what is the license?

You obtain enhanced Redmine as decribed here: http://www.easyredmine.com/software-tour.
Easy Redmine is under same license as Redmine, GNU GPL2. You further obtain 6 months of updates.

Yet he still charges hundreds of euros per plugin.

According to the GPL:

4. Conveying Verbatim Copies.
You may convey verbatim copies of the Program's source code as you receive it, in any medium, provided that you conspicuously and appropriately publish on each copy an appropriate copyright notice; keep intact all notices stating that this License and any non-permissive terms added in accord with section 7 apply to the code; keep intact all notices of the absence of any warranty; and give all recipients a copy of this License along with the Program.

You may charge any price or no price for each copy that you convey, and you may offer support or warranty protection for a fee.

This means, that although he is technically allowed to charge for these plugins, if someone purchases a copy, they then have the right to distribute that plugin for free (or charging whatever fee they want), and so long they follow the GPL nothing can be done to stop them (according to the GPL).

RE: GPL License for Plugins? - Added by Jean-Baptiste Barth 12 months ago

That's precisely the reason why the GPL is so bad. If I want my work in a plugin to be released under an other free software license (such as CC, Apache, BSD/MIT), I'd have to externalize all the code I produce in a third party component and only release a thin layer called a "plugin" to support it. That means I mess up my code because of legal considerations, even though the ability to run the plugin depends on a GPL-licensed base which is already protected strongly and cannot lead to proprietary software. Win!

RE: GPL License for Plugins? - Added by Terence Mill 12 months ago

"You may charge any price or no price for each copy that you convey, and you may offer support or warranty protection for a fee."

Whats bad for me is that you can charge money for distributing the code. That means you can "sell " the code under gpl , and don't have to publish/send it on demand.
Once selled of course one could publish this code for free.

I am no friend of this kind of opensource, because code shall be free on the web repository everytime from my opinon.

RE: GPL License for Plugins? - Added by Harry Garrood 12 months ago

That's precisely the reason why the GPL is so bad. [...] Win!

What? Are you in favour of GPL or not? This is confusing...

Anyway, I was under the impression that Redmine plugins have to be GPL'd. From http://www.gnu.org/licenses/gpl-faq.html#GPLAndPlugins:

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.

There's no dynamic linking (I guess the GNU people can't imagine software not written in C :P) but Redmine plugins definitely make function calls to and share data structures with the Redmine core, and vice versa.

RE: GPL License for Plugins? - Added by Jean-Baptiste Barth 12 months ago

Harry Garrood wrote:

That's precisely the reason why the GPL is so bad. [...] Win!

What? Are you in favour of GPL or not? This is confusing...

The "Win!" is ironical, I'm not in favour of GPL.

RE: GPL License for Plugins? - Added by Harry Garrood 12 months ago

Oh, lol. Yeah, whenever the licence is up to me, I choose MIT, for the same reason. (And also that I can be bothered to read the whole thing, which is not the case for the GPL).

But surely the reason you've given for why you think the GPL is so bad is really a feature? It was designed to not let you release your work in a plugin under another free (or not) software licence, precisely because people can make proprietary software based on it. If that's not what you want, then you shouldn't choose it.

I guess it boils down to whether the GPL is a good fit for Redmine (obviously, this isn't up to me, though).

RE: GPL License for Plugins? - Added by Jean-Baptiste Barth 12 months ago

Not up to me either. Actually I don't know what I'd do if it was: I understand the need to protect redmine core, and I don't think other licenses would offer the same level of protection so... Let's stick with GPL in our plugins hey! :)

RE: GPL License for Plugins? - Added by Holger Just 12 months ago

Jean-Baptiste Barth wrote:

If I want my work in a plugin to be released under an other free software license (such as CC, Apache, BSD/MIT), I'd have to externalize all the code I produce in a third party component and only release a thin layer called a "plugin" to support it.

Well, no. To make my main point clear at first: plugins need to be licensed in way way which is compatible with the main Redmine license, that is the license must be compatible to GPLv2 or later. Plugins do not need to be literally licensed under GPL (in any version). Compatible licenses von GPLv2 include MIT, BSD 3-clause and others. The Apache 2.0 license is also usable with Redmine as long as you use it under GPLv3. Then, all other parts of the systems also need to be compatible with GPLv3. Creative commons is (in most incarnations) not compatible with the GPL, but isn't actually suited for code anyway.

Just think of it like this: if the GPL would prohibit the use of other non-GPL licenses with GPL code, you wouldn't even be able to ship the core Redmine as it itself contains various libraries licensed under public domain, MIT, or the Ruby license.

As for your thin layer, you would need to strongly separate your plugin-layer from your "actual" code to prevent its categorisation as a plugin, e.g. by calling it via command line or a REST service. If you achieve that, you could distribute your code as closed source. But it probably wouldn't be much fun anymore :)

As for the comments against being able to charge money for distribution: If you take that away, the whole business of creating (open source) software for money would go away with it. If people want to charge me for getting some software, that's fine by me, as long as they don't prohibit me or others from further distributing that software under GPL terms.

RE: GPL License for Plugins? - Added by Jean-Baptiste Barth 11 months ago

Awesome! I was totally wrong, sorry about that, and thank you Holger for the clarification. Maybe GPL isn't as bad as I thought ? I'm almost sure the plugin section on the gnu website didn't mention "GPL-compatible licenses" the last time I read it, but I just had a new look (less biased than the first time) and it's mentionned explicitly. Sorry again.

PS: of course my intent was not to produce closed-source code linked to redmine via webservices ;-)

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