Geographic library
Geodesy based library (geodetic and geocentric functions)
Library for OpenStreetMap offline rendering and routing
This is a port of LibRTK on C#, and into a small c/c++ library.
OTB is an open-source C++ library for remote sensing images processing
QNetMap is the library for displaying the map and the objects on it
HistoryLoc is a practical system to track place names over time.
A free library for fast clipping of arbitrary polygons