It's often very useful to be able to give users some help that describes the specific targets, build options, etc., that can be used for your build. &SCons; provides the &Help; function to allow you to specify this help text: Help(""" Type: 'scons program' to build the production program, 'scons debug' to build the debug version. """) (Note the above use of the Python triple-quote syntax, which comes in very handy for specifying multi-line strings like help text.) When the &SConstruct; or &SConscript; files contain such a call to the &Help; function, the specified help text will be displayed in response to the &SCons; -h option: scons -h The &SConscript; files may contain multiple calls to the &Help; function, in which case the specified text(s) will be concatenated when displayed. This allows you to split up the help text across multiple &SConscript; files. In this situation, the order in which the &SConscript; files are called will determine the order in which the &Help; functions are called, which will determine the order in which the various bits of text will get concatenated. Another use would be to make the help text conditional on some variable. For example, suppose you only want to display a line about building a Windows-only version of a program when actually run on Windows. The following &SConstruct; file: env = Environment() Help("\nType: 'scons program' to build the production program.\n") if env['PLATFORM'] == 'win32': Help("\nType: 'scons windebug' to build the Windows debug version.\n") Will display the completely help text on Windows: scons -h But only show the relevant option on a Linux or UNIX system: scons -h If there is no &Help; text in the &SConstruct; or &SConscript; files, &SCons; will revert to displaying its standard list that describes the &SCons; command-line options. This list is also always displayed whenever the -H option is used.