The Micro Focus SupportLine site - https://www.microfocus.com/documentation/extend-acucobol/acumanuals900/ - contains a zipped collection of examples that can be used to demonstrate XML Extensions (and the Xcentrisity Business Information Server): the file is named A Collection of Xcentrisity Examples.
Modern applications often produce PDF documents. Apache FOP (Formatting Objects Processor) is a print formatter driven by XSL formatting objects (XSL-FO) and an output independent formatter. Apache FOP is an open source project of The Apache Software Foundation licensed under the terms of the Apache License, Version 2.0, which permits redistribution under friendly terms to an application developer. Binary distributions of Apache FOP are available for many popular platforms. See http://xmlgraphics.apache.org/fop for more information.
XSL Formatting Objects (XSL-FO) is a standardized, XML-based technology for describing output documents. As such, it is excellent to use with XML Extensions. The examples that use XSL are Envelop, Microsoft Office and OpenOffice documents, and HTML: form-url-encoded.