Hi Vladimir, Here are some thoughts based on reading the online docs. I did not participate in the actual review, so I could easily miss important design and implementation problems. So don't take my comments too serious :-) Section "Tutorial" ------------------------ 1. I don't like that the example hardcodes strings. 2. each line should have a comment about what it does. 3. why po::store(po::parse_command_line(ac, av, desc), vm); instead of po::variables_map vm = parse_command_line( ... ) or vm.store( ... ) ? It would make it clearer what is stored in what. 4. po::variables_map is probably a std::map, right? I think that the way to check if an argument is a bit strange, ie, if (vm.count("help")) should be if( vm.has_argument( "help" ) ) or something. 5. Why is it necessary to remember the type of compresion argument? ie, could cout << "Compression level was set to " << vm["compression"].as<int>() << ".\n"; not be written as cout << "Compression level was set to " << vm["compression"] << ".\n"; ? (if eg. a boost::variant is returned, it would just write the int) 6. Consider desc.add_options() ("help", "produce help message") why don't you have an add_options that take two and three arguments, så the first empty ones can be removed? 7. In po::value<int>(&opt)->default_value(10), I would prefer po::value<int>( opt, 10 ), 8.I don't find this too readable: po::store(po::command_line_parser(ac, av). options(desc).positional(p).run(), vm); compared to po::command_line_parser parser(ac, av); parser.set_options( desc ); parser.set_positional_options( p ); vm.store( parser.run() ); 9. Could this way of specifying composing()/default_value() be of any use option += option<int>( "xx", "xx msg" ), option_with_default<int>( ""yy", var_name, 0, "yy msg" ), option_with_compose< vector<string> >( "zz", "zz msg" ); ?. 10. This po::options_description cmdline_options; cmdline_options.add(generic).add(config).add(hidden); might be po::options_description cmdline_options; cmdline_options += generic, config, hidden; ? 11. Have you compare with the functionality of other program option libraries? I mean, it is always nice to know that this is just the best around :-) br Thorsten