a C++ port of the Java Topology Suite (JTS). As such, it aims to contain the complete functionality of JTS in C++. This includes all the OpenGIS "Simple Features for SQL" spatial predicate functions and spatial operators, as well as specific JTS topology
a Free C++/Python GIS Toolkit for developing mapping applications. Above all Mapnik is about making beautiful maps. It is easily extensible and suitable for both desktop and web development.