This is a server process that runs on a Raspberry Pi and listens for servo commands over the loopback interface. Servo commands are executed serially to avoid drawing too much current from the Pi.
Commands can be sent to port 9338 if you use the servo package's __main__.py, or any port supplied to the ServoServer constructor. Commands use the form pin angle, so 7 90 will set the servo connected to board pin 7 to 90 degrees. Pi board numbering is used, not BCM. The max angle is 180 degrees.
Try it with Netcat:
python3 servo &
echo "7 90" | nc 127.0.0.1 9338