Am I allowed to use a GPL-3 library in a closed source web application?

Question

I am working on an Angular5 web application. It is written in Typescript, and then compiled to Javascript. This is not a real compilation, just a minification

The server which serves the .js files is owned by me, if this makes any difference.

One of the libraries is licensed under GPL-3. The customer (a company) pays for using the software, and the employees of that company can access the software for free.

Does it force me to make the original source of the whole project available for both my customer and all of the users?

Answer 1

You cannot use GPL-licensed code on a proprietary web frontend.

When you include GPL-licensed code into any software, that software becomes a derived work of the GPL-licensed code. Only the GPL gives you the right to publish the resulting software.

In particular, you must offer the source code for the resulting software. The source code is the preferred form of making modifications. Minified JavaScript files are therefore not the source code. The source code can also include build scripts or configuration files that are necessary to run the software, for example a package.json file that specifies dependencies.

You may charge for the software or for services around the software. But once anyone receives the software, they obtain a license under the GPL to use and share this software. You cannot add additional restrictions. So any customer may start offering your software for free. It is therefore common not to charge for the software itself, but for services such as administration, customization, or hosting.

Note that your server backend is generally a separate software. If you use GPL libraries on your frontend, this does not put any requirements on the backend. If you do not want to publish certain code, run it on your backend and have the frontend make Ajax requests to the backend.

Answer 2

As long as the user just runs GPL-2 software, there should be no problem. GPL-3 is different.