I'm building a downloadable digital web product for sale. I want to use an open-source third-party library for my product.

This third-party library has two licenses available:

  • GPL
  • Commercial

I've three scenarios to consider:

  • First scenario: If I include this library in my product with GPL license, my product must also be released under GPL (which I don't want).

  • Second scenario: If I use 'commercial' license of this library, I can release my product under whatever license I want.

  • Third scenario: My product needs this third-party library to extend its capabilities but it does not necessarily need to be bundled with my product source code. I can program my product in such a way that when a customer installs my product, it'll ask the user to install that third-party resource afterward separately (from some open-source GitHub repository).

    This third-party library installation procedure would automatically be done via my product after user confirmation. It will be installed in a separate folder from where my proprietary code is located and my product will then interact with that third-party library via its API.

Question: In the third scenario, do I still need to buy a 'commercial' license, despite the fact that third-party library is not included in source code of my product?

1 Answer 1


You are trying too hard to find a work around the GPL IMHO. If your product is commercial, use the commercial license. If you are installing the GPL library at install time, there is no real difference with bundling it.

  • I want cost savings, where possible, if its legal. Does not license of an open source library dictates how it can be distributed. If distribution channels are different (each channel having appropriate license) how is it illegal? I want to understand the rationale behind. Commented Aug 22, 2017 at 14:57
  • 2
    No the customer won't be breaking the license because they will not distribute anything.
    – Zimm i48
    Commented Aug 22, 2017 at 18:56
  • 1
    @FaisalKhurshid: There are arguments that combining your product with a GPL plugin makes the combination fall under the GPL license (with the associated right to redistribute). These arguments have to my knowledge not been tested in court, especially where the customer has made the combination, but do you want to be the first? Commented Aug 23, 2017 at 10:46
  • 1
    @faisal The GPL considers the complete program that contains or is linked to GPL licensed code to be derived from the GPL licensed code. Commented Aug 26, 2017 at 11:59
  • 1
    This is a quote from GPL FAQ section: "In many cases you can distribute the GPL-covered software alongside your proprietary system. To do this validly, you must make sure that the free and nonfree programs communicate at arms length, that they are not combined in a way that would make them effectively a single program." This proves that not every kind of communication between GPL'ed and proprietary code is prohibited. However, I'm not sure if the situation in question can be regarded communication at arms length. Commented Aug 26, 2017 at 15:13

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.