.topojson

TopoJSON geographic topology file, rendered by mapping libraries like D3

Dedicated renderer

Format facts

MIME type: application/json
Apple UTI: public.json
Stock Quick Look: shown as plain text
Planned approach (census): syntax-highlight
Icon hint: generic-icon
Prevalence: common

Renderer note (from the census)

pure Go JSON parse for arcs and objects

Gotchas: D3.js topology