One benefit of DMX512 vs. Ethernet is that it carries traffic about a mile over a wired network without requiring a repeater. That's one reason most holiday light displays, including the one at Callaway Gardens, use wired rather than wireless networks.

Doug Mobley, founder and CEO of Gilderfluke, says his company's animation control systems and digital audio repeaters are Windows based but are more robust than off-the-shelf PCs.

"PCs don't run the shows because they're not reliable enough," Mobley says. "We have software called PC*Macs that is used for programming. It runs under Windows. It looks a lot like an audio or video editing program except that it's specially designed for animated light shows."

The PC*Macs software has a graphical user interface that allows users to program lights, music or fountains by simply dragging and dropping lines to control how quickly these features get turned on or off.

Gilderfluke's modular bricks start at US$100 each and can support as many as 512 dimmers each.