This is to test XMLCatalog for external entity resolution from the xslt task, both the simple case and using the document() function to refer to a second file (which refers to the entity). This buildfile is called by org.apache.tools.ant.types.XMLCatalogBuildFileTest.java Alternatively, you may try it out by hand by first removing the comment symbols around the echo statements and then calling ant -buildfile xmlcatalog.xml