Is a game "not open source" if all the business-logic code and game assets are open-source, but it relies on a closed-source engine (that it doesn't ship with)?
Doesn't seem much different to me to e.g. writing an open-source game that uses DirectX. DirectX is not, itself, open-source, but it's not really "part of" the game. The game just uses its API; and could equivalently use anything else with the same API (like the DirectX implementation in Wine.)
Doesn't seem much different to me to e.g. writing an open-source game that uses DirectX. DirectX is not, itself, open-source, but it's not really "part of" the game. The game just uses its API; and could equivalently use anything else with the same API (like the DirectX implementation in Wine.)