CLI for Denon AVR-X1000, and possibly others in the AVR serie. It is written in JavaScript, and runs on node.js.
$ npm install jtangelder/denon-remote -g
$ denon
denon$ help
The receiver can be controlled over telnet on port 23. It needs to be connected to your network and the Network Remote setting has to be turned on.
See protocol.pdf for more commands and documentation.