• Installing TopoJSON takes two steps: 1) install Node.js and 2) install TopoJSON
• Once you have TopoJSON installed, you can run GeoJSON files through the TopoJSON program to transform the GeoJSON file to a TopoJSON file
• TopoJSON is comprised of two different APIs - one for converting TopoJSON into GeoJSON in the browser, and one for converting files into TopoJSON format
• By being able to convert from TopoJSON into GeoJSON in the browser, you can take advantage of all of the D3 GeoJSON path tools and projections that are already incorporated into the D3.js library
• By including the TopoJSON JavaScript file in your webpage, you can use TopoJSON files to create GeoJSON Geospatial Data Visualizations in the browser

D3 Video Tutorial Lessons:

• D3 and SVG Paths
• Simplest D3 Map Possible
• GeoJSON
• GeoJSON and GeoJSONLint Part One
• GeoJSON and GeoJSONLint Part Two
• D3 Geo Path
• D3 Map Projections
• Mapping Objects on D3 Map Projections
• Static and Dynamic Data and Web Pages
• TopoJSON Part One