This is an impressive JS graphics library: https://gojs.net/
Simplified maps on top of D3: http://datamaps.github.io/
3 Letter Country Codes are here: https://en.wikipedia.org/wiki/ISO_3166-1_alpha-3
2 Letter Country Codes in JS: https://gist.github.com/maephisto/9228207
Github repo: https://stefangabos.github.io/world_countries/
Cool JS maps: https://www.amcharts.com/javascript-maps/
Country polygons as JSON: https://datahub.io/core/geo-countries
Geojson lint: https://geojsonlint.com/
regular json lint: https://jsonlint.com/
