http://forum.solarus-games.org/index.php/topic,101.0.htmlAh, so they can have separate license from each other.
For the quests in the same part of the game....I think it is okay as long as I keep both tileset images separate. For instance, I won't be able to make a tileset with GPL 2.0 and CC-BY-SA 3.0 combined (mingle) on a single image. This might means that I probably won't being able to use both tilesets on the same map unless Solarus allows two different tilesets to be opened at the same time. Solarus would just be loading different parts of the image and won't actually be producing images that will be used. Kinda like an emulator.
That might be a good feature. A tab where you can choose a different tileset. RPG Maker Ace has a feature like that. With A,B,C, etc tabs. It might help with conflicts with different licenses.