.. _usage:

================================================================================
Using PROJ
================================================================================

The main purpose of PROJ is to transform coordinates from one coordinate
reference system to another. This can be achieved either with the included
command line applications or the C API that is a part of the software package.


.. toctree::
   :maxdepth: 1

   quickstart
   projections
   transformation
   environmentvars
   differences
   projjson

