FortranGIS project includes a collection of Fortran interfaces to some common Open Source GIS (Geographic Information System) software libraries, plus some more Fortran-specific tools.
The libraries interfaced at the moment are Shapelib, GDAL, Proj and ReadOSM.
All the procedures interfaced in Fortran are documented with Doxygen.
The Fortran API for Shapelib is stable and unlikely to undergo any change.
For some common procedures, a Fortran-specific interface is available, thus simplifying the work for Fortran programmers. The Fortran-specific procedures are documented with Doxygen, while for the procedures directly interfaced to the native GDAL functions you should refer to the original GDAL C API documentation.
Here as well a Fortran-specific interface is available for some procedures.
Interfacing to C
The interfacing to the C APIs within this project is done through the ISO_C_BINDING Fortran2003 intrinsic module. This is supported nowadays by most commercial Fortran compilers as well as by the free gfortran compiler. Since version 2.3, FortranGIS makes use of some extra Fortran 2003 features besides bindings to C, thus gfortran version 4.6 or higher is recommended.
The main hosting for this project is now Github, Sourceforge will continue to provide file releases and web pages but source repository is not updated there.