In our article earlier this week looking at the status of X.Org 7.4, one of the features originally planned for integration in this X Server release was MPX, or Multi-Pointer X. While it's been in development for over two years and has been at an experimental state, it's been featured in popular YouTube videos as this is the technology on Linux that allows multiple keyboards and mice to be attached to a single system and MPX allows these input devices to function independently on the same windowing system.