The Smart Nixie Tube is described as the first expandable Nixie Tube display with built-in Arduino Uno compatible hardware. Tyler Nehowig, an Electrical Engineering graduate from the University of Minnesota, is the man behind the project, which is on KickStarter (his website is Switchmode Design).
It's analogue meets digital as the Smart Nixie Tube promises full programmatic control of the tubes. The USP is the ease of connecting the devices to form longer digit displays. You program it exactly like an Arduino Uno. There's also the possibility of wireless control.
Also, the tubes also include a common cathode RGB LED, which allows you - Tyler writes - to "give the warm neon glow of the IN-14 Nixie Tube a cool accent colour".
His project page has a lot of details including a User Guide, Sample Firmware, a Bill of Materials, a Schematic, the Spacer PCB and a Laser Cut Enclosure...
The Smart Nixie Tube is the most open source, flexible Nixie Tube display in the world. It is fully programmable using the unmodified Arduino IDE, and appears as an Arduino Uno running at 16MHz/5V. The Smart Nixie Tube was created to fill the gap that all other Nixie Tube displays create by allowing unlimited digit length -- from one digit to as many as your project requires. Adding more digits is as easy as connecting headers together. You can chain Smart Nixie Tubes together and control them from anything with a Serial Port. Examples include connecting it to a Raspberry Pi to pull in sports scores, the current temperature, or the current time and date.
How do you control the Smart Nixie Tube? You simply open a COM port and send a string of ASCII characters. Apparently the protocol allows full configuration of the digit (both decimal points), the Nixie Tube brightness, and the 24 bit RGB colour of the LED accent lighting.
Once you have sent the data you want to display on your Smart Nixie Tube(s), simply send a ! to latch the data into the Smart Nixie Tube(s). By implementing the latch command, you can load all of your Smart Nixie Tubes with data and then update the displays simultaneously.