What kind of templates can be used (XML,CVS, TXT, etc)? Is there a GUI that business user can use to customize it?
Thanks for your inquiry. In reference to Aspose.Pdf for Java, you can use XML(Aspose.Pdf XSD schema compliant), HTML, TXT, EPUB, SVG, PDF and PCL templates to load and convert to PDF. However for CSV you need to use Aspose.Cells for the purpose.
Moreover, in reference to GUI question, Aspose.Pdf is a class library it does not provide any GUI. However, you may check GroupDoc Viewer Library, a product of our sister concern. It will help you to render and manipulate PDF in a GUI.
Please feel free to contact us for any further assistance.