#mapshaper
▻https://github.com/mbloch/mapshaper
Mapshaper is a program for editing polygon and polyline datasets for mapping. The command line interface has commands for line simplification, polygon aggregation, attribute field calculation, filtering, splitting, table joins and more. The web-based gui focuses on interactive simplification.
Mapshaper can read and write #Shapefile, #GeoJSON and #TopoJSON files.
(...) examples:
Extract the border between two states. mapshaper --filter "STATE=='OR' || STATE=='WA'" --innerlines states.shp
Generate two new fields using JavaScript. mapshaper --expression "STATE_FIPS=CNTY_FIPS.substr(0, 5), AREA=$.area" counties.shp
Zoomed-in view of Norwegian coastline at 5% simplification
#GIS via @nicolaslambert
