That's a good definition. And one that actually matters for open source - where, after all, the goal is for other people to be able to modify your source code.

That's a good definition. And one that actually matters for open source - where, after all, the goal is for other people to be able to modify your source code. But it's completely irrelevant here. If nobody is going to modify your code but you, and if you can produce apps that work great on the iPhone, why should they care whether you write it by editing Objective C or by singing Hungarian love songs into an electric toothbrush?