Peer Monitor is a utility to graphically monitor any given computer to test whether it is "up" or not. By quickly pinging the host’s IP address and listening to the reply, the PM will display a red or a green light depending on whether the echo was returned properly.

It was designed to be used by INTERNET CONNECTION SHARING users, so that they could monitor who was the last person to be surfing and whether they should hang-up and/or shut-down the ICS machine. It should be used by anyone who has a desire to check whether other computers are up (answering ICMP pings).