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Original author(s)Gerald Evenden
Developer(s)Frank Warmerdam
Stable release
6.1.1 / July 1, 2019; 2 months ago (2019-07-01)[1]
Repository Edit this at Wikidata
Written inC++, C
LicenseMIT Edit this at Wikidata

PROJ (formerly PROJ.4) is a library for performing conversions between cartographic projections. The library is based on the work of Gerald Evenden at the USGS,[2] but is now an OSGeo project maintained by Howard Butler. The library also ships with executables for performing these transformations from the command line.


The history of PROJ dates back to the late 1970s,[3] and the first release of PROJ was developed by Gerald Evenden in the early 1980s as a Ratfor program.[4] It was based on the General Cartographic Transformation Package or GCTP, which consisted of Fortran subroutines that could be used to project geographic data. The second release of pPROJ from 1985 was rewritten in C to run on UNIX systems.[5] The third release of PROJ from 1990, named PROJ.3, was expanded to support approximately 70 cartographic projections.[2] Evenden further developed a fourth release in 1994, named PROJ.4. The last version maintained by Evenden was 4.3, released on September 24, 1995.

After over four years of inactivity, Frank Warmerdam became the new maintainer and released version 4.4 on March 21, 2000. As of May 2008, PROJ became part of the MetaCRS project, a confederation of coordinate systems related projects under incubation with OSGeo.

With the release of version 5.0 in February 2018, the software was renamed to PROJ, removing version four (".4") from the name. With the acquisition of the domain name in June 2019, the project was also renamed as PROJ.

See also[edit]

  • GDAL a library that provides a single abstract data model for geospatial data formats which uses PROJ to perform coordinate transformations.


  1. ^ "Release PROJ 6.1.1 · OSGeo/proj.4 · GitHub". Retrieved 2019-07-30.
  2. ^ a b Evenden, Gerald I. (2003-01-01) [1990]. Cartographic Projection Procedures for the UNIX Environment—A User's Manual (PDF). Open-File Report 90-284. U.S. Geological Survey. p. 64. Retrieved 2015-08-14.
  3. ^ Kresse, W.; Danko, D.M. (2011). Springer Handbook of Geographic Information. Springer Handbook of Geographic Information. Springer Verlag. p. 948. ISBN 978-3-540-72678-4. Retrieved 5 June 2019. PROJ and CS-Map are coordinate reference system and coordinate transformation libraries. ... The history of PROJ.4 starts in the late 1970s, when Gerald Evenden was involved in the development of map plotting software, at the Atlantic Geology branch of the United States Geological Survey (USGS).
  4. ^ Evenden, Gerald I. (1983). Forward and inverse cartographic projection procedures. Open-File Report 83-625. U.S. Geological Survey. p. 76. Retrieved 2015-08-14.
  5. ^ Evenden, Gerald I.; Botbol, J.M. (1985). User's manual for MAPGEN (UNIX version); a method of transforming digital cartographic data to a map. Open-File Report 85-706. U.S. Geological Survey. p. 140. doi:10.3133/ofr85706.

External links[edit]