Virtual Radar Server is an open-source .NET application that runs a local web server. You can connect to the web server with any modern browser and see the positions of aircraft on a Google Maps map.
You can see an example of the server's output here.
Virtual Radar Server runs on Windows XP, Vista, Windows 7, 8, 10 and Linux (under Mono).
You will need a radio that is capable of receiving ADS-B transmissions from aircraft. Virtual Radar Server was written and tested using Kinetic Avionic's SBS-1er and SBS-3 radios but it will work with anything that can produce the Kinetic text message format, Kinetic's SBS-3 binary format, the AVR "*", "@" or ":" formats or the Mode-S Beast binary format.
Virtual Radar Server can also show you the location of a simulated aircraft being flown in Microsoft Flight Simulator X. To see this you just need to install Virtual Radar Server on the same computer that Flight Simulator X is running on. You will not need an ADS-B receiver.
If you have an ADS-B receiver, or a copy of Flight Simulator X, then just download the program and give it a go!
If you want to keep abreast of changes to the program then you can: