Actually it's a rpi compute module (not a pi3) - for more accurate description see http://www.raspberrypi.org/blog/compute-module-nec-display-near-you The displays are 40 - 98 inch so probably not what you want on your desk.
Whether plan 9 could run on it depends on NEC documenting the peripherals on their proprietary carrier board that the compute module plugs into.
