ServePDF.com provides a free service to create a sample XML document by reading all fields available in a PDF document. Developers can use this service to verify their PDF Form. Client software will have to POST this XML in order to merge data with the Form.
Two methods of submitting the document are available. The first lets you upload the PDF Form by selecting one from your local Filesystem. The second lets you enter the URL that the service can use to fetch the document.
Sample is an XML document with sample PDFData read from a PDF Form.
Sample PDF Form by Upload