Here is a tool with which one can initiate the creation of a UBL document by synthesizing the element structure of a document.  Using checkboxes one indicates which elements they need in the document, then they serialize the syntax on the web page, then they copy and paste that syntax into their favourite browser to finish it off.  What is created is not schema valid, but it provides an easy way to get started!  And once the software and the (large!) data model is loaded into your browser, there is no interaction with the server and at no time is there any user data transmitted to or stored on the server ... it is entirely self-contained in the browser.

PLEASE NOTE:  this is code running *inside* a web browser using compiled JavaScript, so it runs more slowly than applications running locally in your operating system.  Please be patient.  We've already had feedback that the wait is worth it and the tool is useful, so we hope you feel the same way.