Proj4 is used as a projection tool in MapServer, GRASS GIS, PostGIS, Mapnik, Thuban, OGDI, TopoCad, OGRCoordinateTransformation and various others.
Proj4 has been translated from C to other languages. These sub-projects include:
- Proj4js (JavaScript) – used in OpenLayers.
- CS-Map (C++) – used in MapGuide.
- GeoTIFF/libgeotiff (C++).
- Proj4J (Java).
- SpatialReference.org – website to retrieve coordinate system definitions (obsolete).
Proj4 uses coordinate system definitions defined by the European Petroleum Survey Group (EPSG). Well Known Text (WKT) format.
Website: http://proj4.org/
Licence: X/MIT style Open Source license
Software Version: 4.9.2 (stable)
Supported Platforms: Windows, Linux, Mac
API Interfaces: C, C++, Python, Java, Ruby