PROJ¶

PROJ is a generic coordinate transformation software that transforms geospatialcoordinates from one coordinate reference system (CRS) to another. Thisincludes cartographic projections as well as geodetic transformations. PROJis released under the X/MIT open source license

PROJ includes command line applications for easy conversion ofcoordinates from text files or directly from user input. In addition to thecommand line utilities PROJ also exposes anapplication programming interface, or API in short. The APIlets developers use the functionality of PROJ in their own software without havingto implement similar functionality themselves.

PROJ started purely as a cartography application letting users convert geodeticcoordinates into projected coordinates using a number of different cartographicprojections. Over the years, as the need has become apparent, support for datumshifts has slowly worked its way into PROJ as well. Today PROJ supports morethan a hundred different map projections and can transform coordinates betweendatums using all but the most obscure geodetic techniques.

You can download the source code for PROJ on the download sectionand find links to prepackaged executables in theinstallation section.

In addition to this website the PROJ documentation is also available in PDFform.