"Recently there has been much talk about RandR 1.2 support with
RadeonHD and Nouveau (among other drivers), and as a result we have
been asked many times now 'what is RandR, and why do I care?' Well,
RandR is the 'Resize and Rotate' extension in X.Org and the v1.2
update introduces new functionality such as dynamic hot-plugging
support for display devices. To help those who may be new to Linux
or just never took advantage of this X.Org technology, we have
written a brief guide with some of the RandR basics..."