GDAL is an open source MIT licensed translator library for raster and vector geospatial data formats.
created at Oct. 9, 2012, 9:39 p.m.
PROJ - Cartographic Projections and Coordinate Transformations Library
created at May 22, 2015, 7 a.m.
GRASS GIS - free and open-source geospatial processing engine
created at May 17, 2019, 4:13 p.m.