Can a company modify and use the source code of a GPLed library without selling it or releasing the modification?

Question

I have a specific case here for which I could not find a clear answer here or on other pages. I am working for a company that is interested in using an open source code licensed under GPLv2. The software has machine learning and database components. The machine learning models are used, often in combination with the database, to solve specific tasks. My employer would like to use it internally for its own research. However, we would like to update it so that it works better for us. The modification would aim at improving the models and the database content, so that they are more accurate for the company. This will of course also force us to change the original source code so as to make use of the models. The modified version would be made available on an internal service platform that scientists will use only for internal research. There is no intention of selling/redistributing the software commercially.

Does the company have to release the updates, since technically, the models and the database will be plugged into the source code? If we were to (a) refactor the code to make it flexible so that it would allow any user for dynamically plugging their own sets of machine learning models they train and a modified version of the database, and (b) release the refactored source code under GPLv2: Would we have to release the ML models or any addition to the database content. Your help would be appreciated.

Answer 1

The GPL FAQ is pretty clear about releasing modified versions:

The GPL does not require you to release your modified version, or any part of it. You are free to make modifications and use them privately, without ever releasing them. This applies to organizations (including companies), too; an organization can make a modified version and use it internally without ever releasing it outside the organization.

However, if you do distribute the software to people outside your organisation, then you must do so under the terms of the GPL license and you have to release the sources of your modified version also (at least to everyone that can obtain a copy of the binaries).

The data read by a program, including the contents of a database, and the software of the program itself are completely independent things as far as copyright is concerned. They are licensed independently and their licenses don't affect each other. This also means you can decide to distribute one but not the other.