A library providing vector geometry services
GEOS (Geometry Engine, Open Source) is a C++ library providing vector geometry services according to the Open Geospatial Standards Consortium (OGC). It is a port of the Java Topology Suite (JTS), which is an API of spatial predicates and functions for processing geometry. A number of GIS tools including R, Python, and Qgis rely on this library. GEOS is available under the terms of GNU (LGPL) and is a project of http://osgeo.org.