CmdOption is a simple annotation-driven command line parser toolkit for Java 5 applications. Everything you need is (at least one) simple configuration object. Each field and method annotated with an CmdOption annotation will be processed. Based on this config, CmdOption is able to parse any command line, guaranteeing the declared specification. The result is directly stored in the given config object. When errors occur, CmdOption gives a meaningful error message. Generated output and validation/error message can be localized.