The Dell P4317Q mentioned in the article can take 4 video inputs (2 DP, 2 HDMI) and you can split the screen into up to 4 virtual screens where each virtual screen displays a given input. So you can do fun splits for side-by-side or 4 corners or even 1 tall on the left/right and 2 of 1080p on the other side stacked.
Some of the other monitors which use the same panel cannot do this splitting, as far as I can tell.