FormSIX (Form Simple Interface in XML) package is a set of tools and suggestions for interchanging simple HTML FORM data between Web Browser and Web Server in XML format. For a bigger purpose, FormSIX aids replacing/extending regular CGI with XML by providing client-side JS modules for composing valid XML document. For a smaller purpose, FormSIX helps testing out Internet system design by providing a tool for generating front-end prototype even to a not-yet XML enabled back-end. (FormSIX can even be used to generate Web-based interface to SOAP service.) In fact, the author finds FormSIX pretty handy when it comes to designing DTD.