HEYU is a text based program for remotely controlling lights and appliances for the home or office . Heyu is a text based program for remotely controlling lights and appliances at home or project office.HEYU is available under a free license and open source. Heyu uses the CM11A computer interface to send X10 control signals over power lines to modules which can activate, Off, or Dim attached lamps or appliances. It can store a schedule of planned events in the CM11A memory for execution when the computer is off or disconnected. Heyu can also use an optional CM17A interface to transmit X10 RF signals.