This site started off from Neil Ford's original post
about building your own technology radar. I liked the idea, but
I thought that workign directly with the Json data was a pain. I also didn't like there there wasn't any historical data to work with to see how things changed over time.
So I decided to take what he had started and back it with a data store for historical searching (much like Thoughtworks has on their site).
The code for this is open sourced and can be found at GitHub
if you're interested in checking it out.