Roy Ratcliffe

That is the question!

Brother Faulk has asked another very good question! At X11 2.4.0 under heading Mac OS-X Updates, the XQuartz project writes,

You will need to re-install this package after future OS, and Security Updates delivered through Apple’s Software Update. Additionally, you should reinstall this package after installing XCode.

What the XQuartz folk are saying here is that Apple’s updates will overwrite XQuartz. So users will need to reinstall the XQuartz software distribution in order to get back to XQuartz.

Why two distributions?

The fundamental difficultly here is that two sets of developers (Apple and XQuartz) bundle and distribute X11 for Mac, despite it being one-and-the-same piece of software. Apple bundles their version, XQuartz provide their version.

Which to choose, Apple or XQuartz?

Since the goal is minimal hassle for most users, I recommend sticking with Apple, since you can entirely ignore the X11 question if you have upgraded to Snow Leopard—it includes X11, and Apple will doubtless post upgrades in the normal way as and when. Users can therefore remain blissfully unaware of X11. That would be ideal.

So if on Snow Leopard, ignore X11!

When should you install XQuartz?

There is only one scenario that comes to mind: you are running Leopard 10.5 (no Snow)! In this case you should install X11 2.3.3.2 since this version most closely matches the Snow Leopard version. Thereafter, you need not worry about re-installing because Leopard does not bundle X11 automatically.