Legality of External Program Function Calls
I've been reading through keeperfx code. Its a community patch for Dungeon Keeper 1.
The person stated that instead of creating dungeon keeper from scratch his using the original EXE as a sort of DLL, and is calling the function from it until his wrote a function in place of the old EXEs version.
I was talking with another programmer and he brought up something which I was curious about. Is it legal to do this as long as your not selling the software, and by that I mean using a 3rd parties application to call functions... I mean I would think its ok as long as you have the original copy, are not selling it, and have certain agreement forms for downloads to state that they need the original software before using this "overhead" software.