I searched for a library to manage browser scrolling. I came upon https://wowjs.uk/.

If you look at the bottom, it says it's free, and on its GitHub page the license is MIT.

However, it's a project that is forked from this and if you go to the source repository's website you see that it's priced for commercial usage.

How this could be? How can a fork override the original pricing policy?

Am I safe using the fork in my commercial projects for free?

  • Even the GPL version is free and is likely fine to use in commercial projects, depending on what you're doing. It's important that we're talking about GPL here, not AGPL. If it were AGPL, I'd probably have pause about using such software for a commercial Web project. But GPL software for a commercial Web project? In reality this rarely causes a licensing problem.
    – Brandin
    Feb 21, 2022 at 10:32

2 Answers 2


Until 21st February 2016, the matthieua version was licensed under the MIT license; you can see the commit which changes the license to GPL v3 here. The GPLv3 is of course still an open source license, although deliberately one with more invasive compliance conditions than the MIT license. It appears that the vendors of the product also make it available under a proprietary software license; purchasing such a license enables the purchaser to ignore the GPLv3 requirements.

The graingert version was forked at (essentially) the last commit before the license change, so is still available under the MIT license; that the license has changed on later versions is irrelevant for continued use of the fork.

Am I safe using the fork in my commercial projects for free?

You can use either MIT or GPLv3 code in commercial projects without paying a fee to the copyright holders, as all open source licenses allow for commercial use. Both place some restrictions on what you do which are detailed in the respective licenses.

  • 2
    "that the license has changed on later versions is essentially irrelevant" - Not necessarily irrelevant if you always want to use the very latest version in your code. If you stick to a particular fork (which was/is MIT licensed), then yes, it's irrelevant what the other forks (including the 'official' fork) are doing now with their license.
    – Brandin
    Feb 21, 2022 at 10:28
  • 3
    @Brandin Fair point, edited to clarify (although it is worth noting there are to a very real extent two "latest versions" as there are functional commits in the graingert version not in the matthieua version...) Feb 21, 2022 at 11:04

MIT is a permissive license and essentially allows closed-source forks. Unlike copyleft licenses like GPL family it does not put restrictions on whether the source code must be published.

This aside, nothing prevents anyone from asking a price for open-source software. It's just does not make sense for copyleft licenses as the first person purchases the software will be able to get the copy of the source code and will be able to distribute it without restrictions.

  • However, the matthieua version of the code is licensed under GPLv3. The OP's question is how code under the GPLv3 can be re-licensed under MIT by a third party (and the answer is "it can't"). Feb 20, 2022 at 14:19
  • @PhilipKendall then perhaps OP should edit their question, as it did not give indication of the original license, and was mainly about pricing.
    – rvs
    Feb 20, 2022 at 14:21
  • 3
    The Github page is clear on the licensing though. I would say that vendors of the GPLv3 version are being deliberately obtuse about what can and cannot be done with the GPL version so it is not surprising the OP is confused here. Feb 20, 2022 at 14:27

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.