This library provides access to the GDAL library (http://www.gdal.org/). It provides both direct, low-level access to GDAL and OGR library functions as well as a higher level, more OCaml-like interface.
The API is viewable here.
Linking to the underlying GDAL library is performed at runtime. To initialize:
Gdal.Lib.init_dynamic ();
The init_dynamic function takes an optional ~lib argument which may be
used to specify the specific shared object to link against. It defaults to
libgdal.so.