19 Apr
                
                    2013
                
            
            
                19 Apr
                
                '13
                
            
            
            
        
    
                8:03 p.m.
            
        The first answer here describes the use of extern "C" quite well: http://stackoverflow.com/questions/1041866/in-c-source-what-is-the-effect-of -extern-c It is used to prevent name mangling so you can link together e. g. c object files and c++ object files. I think in Inkscape it isn't necessary at all as the c++ compiler is used for all the compiling.
Markus