PROJ

PROJ
Original author(s)Gerald Evenden
Developer(s)Frank Warmerdam
Stable release
9.6.2  / 6 June 2025 (6 June 2025)
Repository
Written inC++, C
PlatformCross-platform
TypeLibrary
LicenseMIT
Websiteproj.org

PROJ (formerly PROJ.4) is a C/C++ library for performing conversions between cartographic projections. The library is based on the work of Gerald (Jerry) Evenden at the United States Geological Survey (USGS), but since 2019-11-26 is an Open Source Geospatial Foundation (OSGeo) project maintained by the PROJ Project Steering Committee (PSC). The library also ships with executables for performing these transformations from the command line.