Questions about the GNU General Public License

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103
votes
4answers
84k views

Can I use GPL software in a commercial application

I have 3 questions about the GPL here: If I use GPL software in my application, but don't modify or distribute it, do I have to release my application under the GPL? What if I modify some software ...
6
votes
5answers
4k views

Can I use GPL, LGPL, MPL licensed packages with my application and make it closed source?

I saw a company is using BusyBox and also using Gpl + Lgpl + Mpl packages on it, and then they have there own application running on it. Their application is a closed source package. You buy the ...
16
votes
2answers
5k views

Using GPL libraries without modification on a commercial website, do I need to make my source code available? [duplicate]

If I write a public-facing commercial website, and use a GPL javascript library and/or binaries without modifying them (such as plupload), would I be required to make the source for my website ...
12
votes
4answers
5k views

Call GPL software from non-GPL software

Can I (legally) use a program that is released under GPL from another program that I'm writing and not have to respect the GPL (for the program I'm writing)? For example, I have a GUI that uses a ...
4
votes
1answer
2k views

Does a website running modified GPL software have an obligation to release their changes? [duplicate]

If a non-profit organization runs software on its website that is modified GPL'ed software and it acknowledged to be such, do they have a legal obligation to release any changes? They are not offering ...
18
votes
9answers
5k views

Rewriting GPL code to change license

I have found a GPL library (no dual license), which does exactly what I need. Unfortunately, the GPL license on the library is incompatible with the license of a different library I use. I have ...
24
votes
1answer
4k views

How is client-side javascript covered by the GPL?

If I used a GPL-licensed Javascript library in a web application, would I then have to offer source code of the whole site to anyone who downloaded and executed the Javascript lib?
7
votes
1answer
578 views

How do I dual license?

I'd like to open source a project of mine under GPL v3. Additionally, I'd like to sell a license for those who wish to use the code in a proprietary application. How do I go about releasing my ...
6
votes
2answers
403 views

Can I, as author and copyright holder, relicense my code under a more liberal license after it has been published under a more restrictive license?

Say, for example I published my code under GPL. A month after release, I decide evil corporations (*cough*) are allowed to use my code after all, because it's so brilliant and bug-free. Can I just ...
5
votes
4answers
2k views

Relicense BSD 2/3-clause code to GPL

Suppose I release some source code under the new BSD license. Is it allowed for someone else to take this code, make modifications to it and distribute it under the terms of the GPL? From Wikipedia: ...
6
votes
1answer
509 views

What licensing implications (if any) are there when porting code from one language to another? [duplicate]

I'm considering taking an old PHP4 web application and re-writing it using ASP.Net MVC4 in C#. The old application was licensed under GPL2. I'm unsure how this affects my new application, if at all. ...
19
votes
7answers
6k views

Avoid GPL violation by moving library out of process

Assume there is a library that is licensed under GPL. I want to use it is closed source project. I do following: Create small wrapper application around that GPL library that listens to socket, ...
15
votes
2answers
3k views

Can I safely use an open source library in an internal closed-source project?

I m thinking of using iTextSharp, which is licensed under Affero GPL, in an internal closed-source WinForms project. No one outside my company will be using it. GPL (and Affero GPL as well) ...
7
votes
2answers
4k views

Including a GPL-license library in a commercial Java program [duplicate]

I am in the process of helping develop a commercial Java program. We want to use a certain third-party LookAndFeel in the GUI. The problem is that the LookAndFeel library is GPL licensed. Since we are ...
9
votes
4answers
2k views

Use my own GPL licensed code in a commercial product

I am developing a software project in Java/Swing licensed under GPL v3. Later, I want to create a Android application which uses the algorithms of the Java/Swing application. This Android app will be ...
5
votes
2answers
480 views

can a closed source commercial software make system(3) calls to GPL applications (not libraries)?

The closed source commercial software (CSCS), will just make system(3) calls to GPL applications. The user machine will run CSCS and it will call these GPL applications, in realtime, in the very same ...
5
votes
4answers
796 views

Is running an executable as a child process the same as linking a library?

I'm planning on running an executable as a child process in my program (e.g. using Ruby's popen or C's exec() family of functions). However, the executable I'm planning on running is licensed through ...
27
votes
6answers
3k views

What are the Pros and Cons of the GPL? [closed]

I'm looking at licensing some open source software and am looking at the GPL. What are the pros and cons of using this license?
11
votes
7answers
9k views

How to get started in opensource projects and programs [duplicate]

I am interested in starting to learn how to contribute to open source projects and Linux in general. I am a first year B.Sc. Computer Science student this year and we use c++ as our main programming ...
12
votes
9answers
6k views

Can any GPLv2 licensed library be used in a company's internal intranet application?

I am creating an internal application for the company I am contracted to. We wish to use a GPLv2 licensed library in this application. Some points The application is to be used within the confines ...
29
votes
3answers
3k views

Forking GPL project: Do I have full rights on the new fork or still dependencies with the original owner(s)

I am considering the creation of a fork to a small project licensed under GPLv2, and I have some very specific questions I did not manage to answer in my research on various sites and forums. When I ...
8
votes
3answers
7k views

How does the GPL static vs. dynamic linking rule apply to interpreted languages?

In my understanding, the GPL prohibits static linking from non-GPL code to GPL code, but permits dynamic linking from non-GPL code to GPL code. So which is it when the code in question is not linked ...
8
votes
5answers
1k views

What are the consequences of GPL dependencies?

I am developing software for my company and I would like to use some libraries under GPL license. What could be the consequences? Does it mean that the code developed above these GPL dependencies ...
7
votes
5answers
7k views

Using C++/Java to develop software and sell it

I know this question has been asked here before, and I also know that this website is for programming questions only, but please do make an exception, as none of the posts I've come across on this ...
12
votes
1answer
5k views

Confusion about dual license (MIT/GPL) javascript for use on my website

I've read all of the posts I can find on this and I'm still not sure of the answer. I'd like to use a jQuery plugin on my website that is dual licensed under MIT and GPL. Does the dual license mean ...
12
votes
4answers
2k views

Is it OK to learn an algorithm from an open source project, and then implement it in a closed source project?

Reference The post that started it all In order to clear up the original question I asked in a provocative manner, I have posed this question. If you learn an algorithm from an open source project, ...
9
votes
3answers
2k views

Is there a loophole in the GPL that allows proprietary software to be linked with GPL libraries?

Let’s examine a hypothetical scenario: Company X writes a proprietary program (A) that dynamically links with a proprietary library (B). Company Y wants to use a replacement library (C) licensed ...
2
votes
2answers
518 views

Can software with a restrictive open source license (GPL,AGPL) be used as part of a tool chain in a commercial software package? [duplicate]

If we use a nice library like TetGen, generate a simple application-wrapper that simplifies our needs and publish it as open source, can we use it inside some Pipe/Chain of applications used in our ...
10
votes
8answers
4k views

Can GPL-licensed software be resold?

My research group is developing some software for research purposes. The project leader wants the software to be open source and likes the GPL, but wants to ensure that they software cannot be sold. ...
9
votes
1answer
2k views

How do I correctly sub-license a library that is under the MIT license?

How do I correctly sub-license a library that is under the MIT license. I am using and extending the library. The MIT license states that I am free to sub-license the library. Can I simply state: ...
6
votes
3answers
1k views

How to manage, in practice, licence files when combining GPL and BSD licensed code?

I am writing code that uses one library with GPL (not LGPL) license, and one with the 3-clause BSD license. Since I link to GPL-licensed library, my code will need to be GPL as well. How should I, in ...
5
votes
1answer
1k views

Are these steps enough to put my bash script under GPL 3?

I have written a bash script I would like to put under GPL v3. I've read the GNU documentation on How to Apply These Terms to Your New Programs and How to use GNU licenses for your own software. ...
3
votes
2answers
129 views

GPLv3 code in non-GPL software — linking vs. CLI

Suppose there's a GPLv3 app that has a GUI and a CLI. Can I legally expand its CLI (to give me access to functionality hitherto only available via the app's API), release the result under GPL and then ...
8
votes
2answers
2k views

Rewrote GNU GPL v2 code in another language: can I change a license?

I rewrote some parts of Mercurial (which is licensed under GNU GPL v2) in C#. Naturally, I looked a lot into original Python code and some parts are direct translations from Python to C#. Is is ...
2
votes
2answers
63 views

How to properly apply a license

Take for example the GPL-3.0 license. Near the end it states: END OF TERMS AND CONDITIONS How to Apply These Terms to Your New Programs ... So I though that the "correct" way is to use ...
2
votes
1answer
462 views

Do I have to release the code of a MIT licensed software running a GPL library?

Lets say I'm using Node-Webkit, an MIT licensed app runtime. Now, let's say I decide to include a Javascript library which is GPL licensed: while I do not modify the downloaded JS file, I do write my ...
2
votes
2answers
256 views

Does this BSD-like license achieve what I want it to? [closed]

I was wondering if this license is: self defeating just a clone of an existing, better established license practical any more "corporate-friendly" than the GPL too vague/open ended and finally, if ...
0
votes
3answers
522 views

Forking BSD-Project and changing license [duplicate]

Is it possible to fork a project (which I don't own) and change the license from BSD to for example LGPL / GPL / AGPL? I read it would be possible to change fork's license to something compatible to ...
29
votes
7answers
1k views

Choosing a licence for open source projects

I've done some open source projects, and I plan to do more in the future. So far, I've released all my code under GPL, but I've read a few articles which claim GPL is too restrictive for any code to ...
25
votes
3answers
9k views

Can you change code distributed under the MIT license, and re-distribute it under the GPL license?

Is it possible to alter the code of the Chili plugin, which had its latest release on July 2008, and it is licensed under the MIT license, to then license it under GPL? As far I can see, there is no ...
4
votes
2answers
1k views

Distributing a proprietary application together with GPL software [closed]

First, there are many similar questions here, but I found none with direct answers about this specific scenario. If you find a duplicate, please be kind enough to link to the specific answer(s). Also, ...
26
votes
1answer
993 views

If I release a program under GPL, do I have to continue to do so?

Consider this scenario: I am developing a program FooSuite that uses a GPL-licenced library QuuxTools I release the program FooSuite 1.0 under GPL Later on I discover that, for some reason, I need ...
14
votes
2answers
3k views

What does “GPL with classpath exception” mean in practice?

Oracle seems to license all their Java-related open source code under the GPL with a classpath exception. From what I understand, this seems to allow to combine these libraries with your own code into ...
13
votes
1answer
10k views

LGPL 2.1 vs LGPL 3.0 Advantages and Disadvantages

From what I've read, LGPL 3.0 allows you to use the license together with other licenses, more permissive about that(Not even sure about that). From ...
7
votes
3answers
2k views

Can I use this GPL'd PGP library internally in my company?

This PGP library was bought up by Network Associates and then eventually Symantec Corporation. The source code is available and is licensed under the GPL (it was linked to from here). They have a ...
18
votes
3answers
2k views

Must source code released under GPL be human-readable?

In a response to another question, a poster suggested that under the GPL: ...you need to provide the human readable [code], not a whitespace stripped version... Readability would seem to me to ...
9
votes
2answers
3k views

Running software as a service using unmodified GPL(v2+) program as a core dependency: must the SaaS source code be released?

I'm designing a software as a service project which will only be accessed online. I may have a hard dependency on an executable which is covered by GNU GPL (v2 or later). I understand that my code, ...
4
votes
4answers
693 views

Do I have to make source code open, if I use GPLv2 licensed software to derive data

I'm working on a calendar project, on my own. In this project I've to use Swiss Ephemeris. It is licensed under GPLv2 and commercial. With commercial version of license, developers entitled to ...
4
votes
2answers
921 views

Is it legal to distribute a GPLv3 licensed binary through the apples' app store?

I wrote a small multiplatform app and I am considering publishing the osx version in apple store. I've licensed the app under a GPLv3 license. I sort of like the GPLv3 license but I also like the ...
3
votes
2answers
409 views

Is Selling GPL licensed Software Effective?

Let us say that someone writes a piece of software and licenses it under the GPL. Then they go on to sell it. Will this be effective? Won't someone just buy it and redistribute at a lower price? Do ...