Hi Luke and polygonists! I had problems compiling the example files from the doc's main page with msvc-9. None of custom_p*.cpp examples compiled. Also the connectivity_extraction_usage.cpp example failed. (1) connectivity_extraction_usage.cpp: #include <boost/gtl/gtl.hpp> must be replaced by #include <boost/polygon/polygon.hpp> namespace gtl = boost::polygon; has to be added. (2) custom_point.cpp: compilation yields: 1>.\custom_point.cpp(75) : error C2757: 'gtl' : a symbol with this name already exists and therefore this name cannot be used as a namespace name 1>.\custom_point.cpp(77) : error C2143: syntax error : missing ';' before '<' 1>.\custom_point.cpp(77) : error C2913: explicit specialization; '::geometry_concept' is not a specialization of a class template and many errors more after replacing gtl:: by boost::polygon:: and namespace gtl { ... } by namespace boost { namespce polygon { ... } } and adding typedef int coordinate_type; to struct CPoint the code finally compiled. Are these examples intended to be excercises ;) HTH Joachim