I'll try and add some content before sending a message this time ;) Platform: 2K Compiler: VC6 SP5 Library: stlport-4.0 Boost: 1.27.0 Build Tool for Boost: Jam Run-time Library: Multithreaded DLL/Debug Multithreaded DLL I've got a couple of problems trying to get my app to link against regex. I've tried linking to the debug and release versions of both the DLL and non-DLL versions of the regex library and in each case I get errors about unresolved external symbols for w32_regex_traits. w32_regex_traits.obj has been produced by Jam. In addition the static version winges about lots of locally defined symbols. I've specified BOOST_REGEX_NO_LIB as the generated filenames are not what Jam produces. Here's the full details: --------------------Configuration: request_line_test - Win32 Debug-------------------- Linking... http_request_line.obj : error LNK2001: unresolved external symbol "__declspec(dllimport) public: static void __cdecl boost::w32_regex_traits<char>::transform_primary(class _STL::basic_string<char,struct std::char_traits<char>,class _STL::allocator<c har> > &,class _STL::basic_string<char,struct std::char_traits<char>,class _STL::allocator<char> > const &)" (__imp_?transform_primary@?$w32_regex_traits@D@boost@@SAXAAV?$basic_string@D U?$char_traits@D@std@@V?$allocator@D@_STL@@@_STL@@ABV34@@Z) http_request_line.obj : error LNK2001: unresolved external symbol "__declspec(dllimport) public: static bool __cdecl boost::w32_regex_traits<char>::lookup_collatename(class _STL::basic_string<char,struct std::char_traits<char>,class _STL::allocator< char> > &,char const *,char const *)" (__imp_?lookup_collatename@?$w32_regex_traits@D@boost@@SA_NAAV?$basic_string @DU?$char_traits@D@std@@V?$allocator@D@_STL@@@_STL@@PBD1@Z) http_request_line.obj : error LNK2001: unresolved external symbol "__declspec(dllimport) public: __thiscall boost::bad_expression::bad_expression(class _STL::basic_string<char,struct std::char_traits<char>,class _STL::allocator<char> > const &)" (__ imp_??0bad_expression@boost@@QAE@ABV?$basic_string@DU?$char_traits@D@std@@V? $allocator@D@_STL@@@_STL@@@Z) http_request_line.obj : error LNK2001: unresolved external symbol "__declspec(dllimport) public: static class _STL::basic_string<char,struct std::char_traits<char>,class _STL::allocator<char> > __cdecl boost::re_detail::w32_traits_base::error_strin g(unsigned int)" (__imp_?error_string@w32_traits_base@re_detail@boost@@SA?AV?$basic_string@DU ?$char_traits@D@std@@V?$allocator@D@_STL@@@_STL@@I@Z) http_request_line.obj : error LNK2001: unresolved external symbol "__declspec(dllimport) public: static void __cdecl boost::w32_regex_traits<char>::transform(class _STL::basic_string<char,struct std::char_traits<char>,class _STL::allocator<char> > & ,class _STL::basic_string<char,struct std::char_traits<char>,class _STL::allocator<char> > const &)" (__imp_?transform@?$w32_regex_traits@D@boost@@SAXAAV?$basic_string@DU?$char_ traits@D@std@@V?$allocator@D@_STL@@@_STL@@ABV34@@Z) Debug/request_line_test.exe : fatal error LNK1120: 5 unresolved externals Error executing link.exe. request_line_test.exe - 6 error(s), 0 warning(s) Thanks, - Dale.