I just looked at a contraption with 24v AC motors and solenoids controlled by relays. As expected, it goes mildly haywire when he turns one of these motors on or off. If it was DC, I'd put a diode across each gizmo. In an AC system? Umm. Perhaps MOVs? He just ordered some 56v MOVs from Digikey.
It's operate by a beaglebone running a program written in Ruby.
"You write in Ruby?"
"With your name, I figured you'd be an expert!"