Hot answers tagged

11

Maybe. Yes, you have to comply with the terms of the host application's license. However, a copyleft platform can choose to go either way. Some copyleft applications have a specific licensing exemption for plugins; in other cases, the technical architecture does not result in a derived work and thus an obligation. Consider a plugin architecture where a ...


11

Since you explicitly say the plugin runs as a separate process from the closed-source program, the FSF presents the legal opinion that a plugin would probably be a separate work from the original (emphasis mine): Can I apply the GPL when writing a plug-in for a non-free program? If the program uses fork and exec to invoke plug-ins, then the plug-ins ...


7

Fortunately, this is not a tricky case at all. You are not in any way bound by any terms in the GPL if you are not distributing software that is licensed to you under the GPL. Neither you nor your users are distributing software licensed to them under the GPL. Your users are always free to use free software in any way they like. The GPL doesn't forbid - in ...


6

To answer the question of the form "You've created a plugin for X with GPL'd libraries; can you force X to be open sourced?" -- absolutely not. Instead, what may be true (see the final paragraph for the corresponding "might not") is that that plugin cannot be legally distributed in combination with the main program unless the main program is also under the ...


5

IANAL/IANYL. That said, the devil, as usual, is in the details, and you don't give us much information about how these adaptors work. If, for example, the B-C adapter is a piece of software that works by linking against libraries that form part of B, and also against libraries that form part of C, then you've created a single, large, derivative work of ...


5

The GPL's principal obligations, those governing source distribution and GPL-covers-all, apply only when the program is itself distributed, rather than used. As long as neither you nor anyone else distributes the program and the plugin together, there will be no GPL violations occasioned; certainly not by those choosing to obtain the parts separately and ...


5

Can I write a plugin to interface the closed-source software with the GPL library, for my private use? Yes, the GPL does not affect private use. This is both due to private use exception in copyright law, and because the GPL explicitly says that it only applies to distributions of "something" containing GPL code. Can I distribute the plugin as a compiled ...


4

The answer is: A host application's license apply to plug-ins written for it if the License is a Copyleft License (such as the GNU GPL), and you distribute the plugin with the application (so no private use exception apply). (The same rules do not apply for a permissive license such Expat (MIT), but your question specifies Copyleft.) Drupal is a CMS that ...


3

TL;DR: Keeping your library closed source will violate the GPL. As already mentioned in the comments, your question is answered by the FAQ: If the main program and the plugins are a single combined program then this means you must license the plug-in under the GPL or a GPL-compatible free software license and distribute it with source code in a GPL-...


3

You intend to make a "plugin for a plugin" for Wordpress, where the plugin you're writing code to connect to is itself GPLv2, and you wish to know what your licensing obligations are. The short answer is that GPLv2 s2b says that You must cause any work that you distribute or publish, that in whole or in part contains or is derived from the Program or any ...


3

My first question was whether FileBird was really under GPLv2; they don't exactly go out of the way to make the license a salient. But after some digging it looks like you're right. That given, what you propose - removing the billing and registration hooks - is completely lawful. You don't even have to use another name, though it would probably be kind of ...


3

The traditional way to think of a shared address space is when you have a process that isolates memory regions. This of course would not apply to an OS that does not have a notion of a process. But would not FreeDOS allocate separate memory regions to each of the TSR? Actually the FreeDOS wiki is quite clear and explicit on this topic: Additionally, ...


3

The existing answer is perhaps not clear enough. A third party cannot force the GPL on you. This is not specific to the GPL. They couldn't force a BSD or closed-source license on you either. Imagine if it was possible. Microsoft would need to create one closed-source program and have the Linux kernel run it, to close down Linux ! And vice versa you could ...


3

The software is under an open source license, which per the open source definition guarantees you may use it for whatever purpose you want. The license used is the GPLv3, which is a strong copyleft license. It requires that if you distribute your software that includes this plugin, or make a derivative work based on this plugin, the entire work must be ...


3

Yes unless you specify otherwise. The plugin is derived from the API which specifies which functions the plugin needs to export and what they should do. If you released X under GPL you can add an exemption for the plugins and dual license the API itself with a less restrictive license that allows non-GPL license for the plugin. That way you can allow ...


2

Yes. Many open source CMS projects cover this in their FAQ, Drupal and Wordpress being two notable instances. The Drupal FAQ #7 states that plugins are derivatives of the original; the Wordpress Support forums tell you the same thing. From there, it just depends on how the original is licensed. Wordpress is under the GPL, so derivative works must also be ...


2

The readme file of the project declares the project under the GPLv3. Be wary, anything that uses it is forced to be under the GPLv3 as well. This is a strong copyleft license. Warning call! The project however, doesn't actually include a license file, thereby making the project improperly licensed, and the GPL then legally doesn't apply to the project (if ...


2

Yes, you can achieve your goal with the GNU GPL, except for prohibiting commercial use. Section 7 of the GNU GPL states that you may add "additional terms" as long as they do not restrict the rights granted by the GNU GPL. In your case, you want to grant an additional exception from the conditions in the GNU GPL or at least clarify your point of view. So ...


2

The method of communication is not relevant. If you don't modify the GPLv2 program, and your proprietary program is developed independently from the GPLv2 program, there is no derivation work, so you can use the GPLv2 program without restrictions. If you modify the GPLv2 program, things are grey. On both side you will have to code the communication part, ...


2

I believe requiring .js files is definitely a dynamic linking. It's not much different from linking a library in your project for the use of library's functionality, which would be considered using the library as a plugin by GPL: Linking a GPL covered work statically or dynamically with other modules is making a combined work based on the GPL covered work....


2

Tough question. I'd say that if the the plug-in does not use code from your software, then it is not a derivative work but a good lecture can be this: https://www.drupal.org/about/licensing, where there is a good explanation (Drupal call the plugin "module") about the topic.


2

No, what you propose is not legal. The LGPL license is written in such a way that the linking exception only works one way. All the code that an LGPL library depends on must be under a GPL-compatible open-source license Code that depends on an LGPL library may use a GPL-incompatible license. The fact that the LGPL library gets used by a GPL application is ...


1

If this is an application you are developing, there's no problem: as the copyright holder, you can do whatever you like. If you want to permit other people to develop closed-source plugins for your application, it's recommended that you add an exception clause to your license statement (eg. "Plugins for MyApplication that use the documented plugin API can ...


1

For copyright licensing, only the dependencies of the deployed software are relevant. The licenses on your build tools can be completely ignored1. A file like 3RD_PARTY_LICENSES also only needs to refer to the licenses of your dependencies. 1: the exception here are tools that copy part of their source into the output. Those would effectively be a ...


1

First GPL is commercial (see https://www.gnu.org/philosophy/words-to-avoid.en.html#Commercial ) Now to answer the question: A third party, can not affect the licencing of your code. That is if a 3rd party, writes a plugin, then you have not done anything wrong. However if you create a plugin system as a way to get around the GPL, then you have not got ...


1

Since you are modifying an existing plugin, then there isn't much room to play. But if you would create plugin from scratch, then you wouldn't need to release it under GPL. Using libraries or creating your own plugins from scratch are not derivative work since you aren't modifying existing code.


1

I am not a lawyer, but here is my two cents. Although the GPLv3 strongly recommends that you include a comment header declaring the license and the copyright information in each individual file, I don't believe it's required. https://www.gnu.org/licenses/gpl-howto.en.html Unless stated otherwise in individual files, I would say the project as a whole is ...


1

IMHO your question boils down to: can a piece of GPL-licensed code load arbitrary code under non-GPL or other licenses assuming it does not know about any of this other code ahead of time? The closest thing that comes to mind would be an OS user space such as the Linux user space. Linux does not know anything ahead of time about your program. Does its GPL ...


1

As the license is GPL-compatible there should be no problems (if the license has no share-alike condition). If you are still unsure you could simply contact the creator of the software you want to make your plugin for.


1

Unfortunately, this is a tricky case. ;) Does your program interact with GPL-incompatible code? And if so, how? If your program only interacts with GPL-compatible code then obviously you're good to go but I guess you wouldn't have asked the question if that were the case. It depends on what your software is doing but there's a risk that it's a "GPL wrapper"...


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