QGIS

QGIS ® is a free and open-source cross-platform desktop GIS (Geographical Information System) application that supports viewing, editing, and analysis of geospatial data. In other words, QGIS® is a GIS application designed to deal with spatial data. Spatial data consists of points, lines, and polygons as well as other background imagery and reference data. Knowledgeable users analyze this data to identify trends and determine solutions to real world problems.