Spatial4j is a general purpose spatial / geospatial ASL licensed open-source Java library. It’s core capabilities are 3-fold: to provide common shapes that can work in Euclidean and geodesic (surface of sphere) world models, to provide distance calculations and other math, and to read & write shapes from formats like WKT and GeoJSON. Spatial4j is a project of the LocationTech Industry Working Group of the Eclipse Foundation.