My interpretation of their FAQ[1] on it is that shelling out and IPC are fine, while linking is not. As you say, it's ultimately up to the courts to decide on.

My interpretation of their FAQ[1] on it is that shelling out and IPC are fine, while linking is not. As you say, it's ultimately up to the courts to decide on. [1]: https://www.gnu.org/licenses/gpl-faq.html#MereAggregation https://www.gnu.org/licenses/gpl-faq.html#MereAggregation