Xcode 4.3: where do xcode-select, xcodebuild, xcrun, etc, come from?

[James Berry]

The idea behind Xcode 4.3, as I understand it, is that it can be a first-class App Store app: it doesn't need to install anything as root, or outside of its sandbox: it uses external installers for this (witness the Command Line Tools installer, etc).

So if that is indeed the case, I have a question some of the tools of Xcode that are installed in /usr/bin: xcodebuild, xcode-select, xcrun, etc.

My questions are these:

	(1) Do these tools exist on a machine if Xcode has never been installed? (i.e., are they part of the core os?)

	(2) Are these tools installed when Xcode 4.3 is first run? (or at some later time?)

	(3) Are these tools installed only when the Command Line Tools installer is run?

I don't have a virgin machine to use to get to the bottom of that, but if anybody can help with answers it would be useful…

James