parse-argv (rubygems): Just write the help text for your application and ParseArgv will take care of your command line. It works sort of the other way around than OptParse, where you write a lot of code to get a command line parser and generated help text. ParseArgv simply takes your help text and parses the command line and presents you the results.  You can use ParseArgv for simpler programs just as well as for CLI with multi-level sub-commands (git-like commands). ParseArgv is easy to use, fast and also helps you convert the data types of command line arguments. 
Keywords: argv|argv-parser|cli|parse|parser|ruby|ruby-gem