Nodemap is a project mainly written in JavaScript, it's free.
Experimental AMQP to js client mapping app
To run, type:
node server.js
Visit:
http://localhost:8600
Track a hit by opening another browser window and visiting:
http://localhost:8600/stat?lat=0.00,lon=0.00&title=Bacon
An icon will appear on the original map at latitude 0, longitude 0, with the title "Bacon".