Another question remains regarding the docs though: why is it bad to always compile main.c with a C++ compiler?

For the whole thing to work, it may also be necessary to link the entire application with a C++ compiler; that in turn may bind to the C++ library. Linking with the system's C++ library means that the Python executable cannot be as easily exchanged between installations of the operating system - you'd also need to have the right version of the C++ library to run it. If the C++ library is static, that may also increase the size of the executable. I can't really point to a specific problem that would occur on a specific system I use if main() was compiled with a C++ compiler. However, on the systems I use (Windows, Solaris, Linux), you can build C++ extension modules even if Python was not compiled as a C++ application. On Solaris and Windows, you'd also have to chose the C++ compiler you want to use (MSVC++, SunPro CC, or g++); in turn, different C++ runtime systems would be linked into the application. Regards, Martin