The nixie tube is a gas discharge vacuum tube, used as a display for numeric and other symbols. The term 'nixie' is actually a trademark of the Burroughs Corporation that has now become a generic name. It was widely used as test equipment display's in the 1950's and early 1960's, as well as calculators, measurement readouts and other instrumentation.
Nixies disply elements operate typically with approx 1mA of current from a 170v DC supply, much in the same approach as basic neon lights. They range in size from miniature (approx 8mm) to extra large (100mm) figure sizes.
A nixie tube display system was used in the year 2000 movie by Warnerbros titled "The Dish". The movie mockup control display using nixies is now on display in the Parkes Radioastronomy centre visitors centre.