This is F.O.B. (Flexible Orange Box), inspired by the popular S.O.B. (Software Orange Box) program for Windows.
When connecting SIP FXS devices with a Class 5 switch, the ATA will not see a Call Waiting presented to it when there is a Call Waiting. Thus, it is necessary to signal the FSK directly to the CPE in-band from the switch. Asterisk does not have any provision to do this, so this needs to be done with an external program.
This program is intended to be a legitimate Type II Caller ID Generator, used for the purpose of Call Waiting Caller ID (Of course, functionally, it can be used just like any other orange box to spoof call waitings if desired - we are not responsible for any misuse of this program). This allows you to send Call Waiting Caller ID to a remote endpoint, even if no Call Waiting is presented to the remote endpoint (e.g. Analog Telephone Adapter), allowing for CWCID to be provided even when advanced bridging capabilites are being used, by "orange boxing" in band for legitimate purposes.