Germany-based display and touch solution provider Lang AG demonstrated their latest display, a 55" transparent touch-enabled Full-HD OLED. This is the first time, I think, that a touch-enabled 55" transparent OLED was demonstrated:
Lang's transparent OLEDs are probably produced by Samsung Display, which are starting to produce 55" transparent OLEDs. LG Display also demonstrated similar panels, but it seems they are still just prototypes.
Other companies are also launching 55" FHD transparent OLEDs. In February 2015, Planar Systems unveiled a 55" Full-HD transparent OLED prototype. Planar started accepting orders for the Planar LookThru displays in November 2015 for $14,995, and the displays should start shipping shortly. Eyevis also announced similar displays.