Hello, I've used the following command to build boost on a mac: ./b2 -a toolset=darwin architecture=x86 macosx-version=10.5 macosx-version-min=10.5 threading=multi link=static address-model=32_64 --without-mpi stage When i link the following source: bool runJavascript(const char * jscode) { std::string javaScriptCode; try { javaScriptCode = boost::locale::conv::from_utf<char>(jscode, "ISO-8859-15"); } catch(...) { javaScriptCode = jscode; } } Then i get the following error message, on windows this work just fine: Undefined symbols for architecture x86_64: "std::basic_string<char, std::char_traits<char>, std::allocator<char> > boost::locale::conv::from_utf<char>(char const*, char const*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, boost::locale::conv::method_type)", referenced from: ProxyMethod(char const*, char const*, void*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)in JavaScriptRunner.cpp.o ld: symbol(s) not found for architecture x86_64 collect2: ld returned 1 exit status Does anyone have an idea on how to solve that? Thanks in advance