[thristian]

My understanding is that the driver-makers that cooperate with Xorg and the kernel implement the official multiple-monitor stuff nicely and everything more or less Just Works. Unfortunately, that's pretty much only Intel. nVidia and AMD like to do everything themselves rather than cooperate, and so things like multiple-monitor support can require driver-specific config tools, or messing with config-files to tell the drivers to emulate the standard interfaces so the standard tools will work.