An XHTML+XForms file that runs in Form Runner or in the XForms sandbox - This is the preferred way of submitting a test case. Most problems with XForms can be shown in one single XHTML+XForms file. If you need the XForms to call a service with an <xf:submission>, you can simulate this by placing an XML file that contains the response from that service on a public web site, and changing the <xf:submission> to point to that file. If you don't have a server of your own that you can use for this, a free hosting service will work. With Form Builder, you can open the form source with "Edit Source" and copy the form definition from the editor.