We have an word game commercial mobile application for which we want to use dictionaries for various languages. Most of them have GPLv3 or CC-NC3 licenses.
We modify the dictionaries: basically, we filter out some unallowed words and convert them from TXT to DAWG. The resulting files are not distributed along with the app. The app downloads a list of them, the user chooses one and uses it. The user is not able to provide his own dictionary (that is, the application downloads from fixed URL). However, if he asked us to add one, we may do so.
- is this usage complying with GPLv3?
- is this usage complying with CC-BY-NC3?
It is obvious, that a commercial app can work with GPL data. The problem probably reduces to whether our way of usage is considered "part of an application" or "linking".