Powerful command line and configuration file parsing for C++, Python, Ruby and Java (others to come). This tool provides many features, such as separate treatment for options, variables, and flags, unrecognized object detection, prefixes and much more.
GetPot is a great tool to use in C++, Python, Java, and Ruby. It makes it extremely easy to parse the command line. For my taste, it is much easier to use than the 'getopt' type of tools.