Welcome to Proj4J

Proj4J is a Java library to transform point coordinates from one coordinate system to another, including datum transformations.

The core of this library is a port of the ​PROJ.4 C library. The basic algorithms, concepts and coordinate system definitions supplied by PROJ.4 have been exposed via a class model which follows standard Java conventions and OO best practices.

Proj4J is a part of the ​MetaCRS group of projects, hosted by ​OSGeo.

Download

• The current development source is available via anonymous SVN from ​http://svn.osgeo.org/metacrs/proj4j.

Documentation

• The current ​PROJ.4 documentation.

Related Resources

• The PROJ.4 site has a comprehensive list of ​resources dealing with Coordinate Systems in general and the PROJ.4 library in particular.