The question in the title.
Whence such a question - for a long time already there is an idea to create a pirate "emulator", for those who have Windows, but who want to develop for OS X and iOS.
I use VPS myself, but there are certain limitations, and it still costs money.
The "emulator" will be a pirated image of OS X running in VirtualBox or VMWare, of course modified for ease of use, like Genymotion, it is also based on the VirtualBox SDK.
With reverse engineering, everything is perfect, if necessary - I can disassemble the entire OS X with Xcode and iOS Simulator and the entire VirtualBox, make x86 from x86-64 modules, take the old OS version and "splice" the components with a new one, finalize VirtualBox much better than its creators, so it will all work even on AMD without AMD-v and with 2 GB of RAM, etc.
But time!
Therefore, at first, it is necessary to limit ourselves to what is possible to achieve quickly enough so that it is as “unpretentious” as possible to the host power, so that it does not require Intel VT-x, but works with AMD-v, and it is better without hardware virtualization to run on VPS with Windows Server.
And this is offhand OS X 10.6 (it can even be 32-bit), you can't count on more.
And, therefore, Xcode 4.3-4.6, corresponding to the era of iOS 6 and iPhone 4.