Hacker News Reader

+ the hardware mandatory to build and submit Apps to the AppStore, right?

Yes. Apple forces you to buy their overpriced hardware if you want to develop for their platform.

Xcode comes with an iOS simulator so you don't need hardware, but it would be a bad idea not to test on an actual device.

How do I run xcode on Linux or Windows?

In qemu.

Is this legally possible without software piracy? Can you link me to instructions? Does apple have documentation anywhere?

IANAL.

I don't know if Apple has documentation somewhere.

Xcode only runs on Apple hardware. (a)

a. Well, if Apple got their way when it came to Hackintoshes.

You got me there.