An orange box is a piece of hardware or software that generates caller ID frequency-shift keying (FSK) signals to spoof caller ID information on the target's caller ID terminal. It takes advantage of call waiting caller ID (also called off-hook caller ID) by mimicking the phone company's central office equipment and sending the call waiting tone followed by the audible caller ID data. An orange box can also be used to spoof Caller ID information sent after an incoming call rings, if the user has direct access to the target's phone line. One proposal to accomplish this involves an orange box used in conjunction with a magenta box, which in combination is called a vermilion box.
In software engineering, an orange box is any mechanism that records the sequence of events leading to a crash, in analogy to the flight data recorder (FDR) in airplanes, which is typically housed in an orange box to ensure visibility in the wreckage after a crash. The FDR is popularly known as a black box.