Nixie Clocks. An interesting combination of Cold War era Nixie tubes, today's microprocessors and surface mount technology.

Nixie tubes were one of the first styles of digital displays. They used vacuum tube technology of the day. They're known for their individually formed numbers and soft orange glow.

Nixie's quickly went out of fashion due to high cost, high voltage interface, and delicate construction.

I prefer the look of Nixie tubes to the more common 7-segment displays of today.