Wrong license - must be GPL due to GPL dependency

[ornicar]

This project, or at least the pgn-viewer module, must be released under the GPL license.

The reason is that it uses chessground which is licensed as GPL-3.0.
According to the terms of the license, any work depending on chessground must be released itself as GPL-3.0.

• http://greendrake.info/publications/js-gpl#do-i-have-to-gpl-my-client-side-javascript-code-if-i-am-using-a-gpled-library-in-it
• https://tldrlegal.com/license/gnu-general-public-license-v3-(gpl-3)

By extension, all programs or libraries depending on PgnViewerJS must also be released as GPL.

This includes:

• https://eloguessr.com/
• https://github.com/xeyownt/mwpgnjs
• https://github.com/mliebelt/PgnViewerJS-WP
• all the forks https://github.com/mliebelt/PgnViewerJS/network/members
• all programs depending directly or indirectly on PgnViewerJS

[mliebelt]

Thank you for bringing that to my attention, you are right. The only point here is, that not all of the forks are based on the current version, a lot of them are pretty old, and use the old version, that had chessboardjs inside. That is true as well for https://github.com/xeyownt/mwpgnjs, I checked their test web site and the sources, and found no reference to chessground.

I will fix that license soon, and do whatever I can do to ensure that this is followed on dependent projects.

The relevant timepoint / tag is https://github.com/mliebelt/PgnViewerJS/releases/tag/v.0.9.7 that means

• Someone that has forked before that date, and never synchronized later is ok.
• All other should follow the change in license then.

[ornicar]

Thank you!

[mliebelt]

Forgot to update the top README.md file, after moving the licenses to the right places.

[ornicar]

I see you licensed the viewer subproject as GPL, thank you for that. Indeed the reader subproject can remain under the Apache license.

At the moment the root project that contains both viewer and reader is unlicensed. I think, but I may be wrong, that it should be licensed as GPL. The reasoning is that it contains GPL code (the viewer) and is therefore GPL itself.

I think It's not a problem for a GPL project (root) to contain Apache licensed code (reader). I'm also not totally certain of that. Licensing is hard :-/

[mliebelt]

Thank you for your comment. I am not sure about that either. For me, the repository as a whole contains the history, but I publish the packages through NPM. There, I have pgn-reader and pgn-viewer with the correct licenses. Of course, anyone can clone/fork the repository, but the README makes it clear that the viewer is licensed as GPL. But I can add the license again (GPL) to the repository, because the usage by all will be to use the viewer, not the reader.

[ornicar]

Thanks. I think it's the correct decision. A repository containing GPL code has to be licensed as GPL.