PROJ
| PROJ | |
|---|---|
 | |
| Original author | Gerald Evenden |
| Developer | Frank Warmerdam |
| Stable release | 9.8.1 
/ 10 April 2026 |
| Written in | C++, C |
| Platform | Cross-platform |
| Type | Library |
| License | MIT |
| Website | proj |
| Repository | |
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.