Visualizations based on D3.js
GeoJSON (geojson.org) is, like it sounds, a way of encoding geodata in JSON format. Each feature in a featureCollection is a JSON object that stores the border of the feature in a coordinates array as well as metadata about the feature in a properties hash object. For instance, if you wanted to draw a square that went around the island of Manhattan, it would have corners at [–74.0479, 40.6829], [–74.0479, 40.8820], [-73.9067, 40.8820], and [–73.9067, 40.6829],