TURF
A modular geospatial engine written in JavaScript
...Turf can be added to your website as a client-side plugin, or you can run Turf server-side with Node.js. Modular, simple-to-understand JavaScript functions that speak GeoJSON. Turf is a collection of small modules, you only need to take what you want to use. Takes advantage of the newest algorithms and doesn't require you to send data to a server. TypeScript definitions are packaged with each module. No DefinitelyTyped packages required. Turf uses GeoJSON for all geographic data. Turf expects the data to be standard WGS84 longitude, latitude coordinates. ...