Hi, I've tested boost.program_options, where I get linker error: $ LANG=en g++ -DBOOST_ALL_NO_LIB -DDRIVER -O -I /usr/local/boost_1_37_0_beta1/include/boost-1_37/ cmdlineopts.cpp -o cmdlineopts -L /usr/local/boost_1_37_0_beta1/lib/ -l boost_program_options ... cmdlineopts.cpp:(.text+0x99): undefined reference to `boost::program_options::options_description::m_default_line_length' ... cmdlineopts.cpp:(.text+0x1ff): undefined reference to `boost::program_options::options_description::m_default_line_length' ... cmdlineopts.cpp:(.text+0x381): undefined reference to `boost::program_options::options_description::m_default_line_length' collect2: ld returned 1 exit status nevertheless compiled with -DBOOST_ALL_NO_LIB or -DBOOST_ALL_DYN_LINK Did I miss something? Regards, Olaf