With Filestar you get 6 different skills for working productively with TopoJSON (.topojson) files.
About .Topojson
Name
TopoJSON
Extension
.topojson
Category
GIS
Developer
Mike Bostock
Description
TopoJSON is a file format for encoding geographic data structures, based on the GeoJSON format. It encodes geometries more efficiently and supports topology, which enables more accurate representations of geographic objects. TopoJSON eliminates redundancy and simplifies data, making it smaller and easier to work with.