Sonar is a Java program that pings large numbers of IP addresses (a bit like nmap - to see whether
there is a computer responding at that address) and records the results in a text file.
SonarNavigator is a Java3D application that imports data files containing IP addresses from Sonar and displays them in 3D using a simple transformation to turn the A.B.C.D standard IPv4 address notation into 3 dimensional coordinates.
You can navigate through the 'IP space' a bit like a flight simulator. If you imagine a 3D lattice structure, the intersections represent possible addresses, which are either occupied by an object if the IP address returns a ping packet, or are blank if there was no response.
Of course, it was inspired by William Gibson's cyberpunk novels when Case jacks into the matrix...