Apache XML-RPC supports SAX 1.0 and can therefore be used with any compliant XML parser. The default parser is John Wilson's MinML parser which is included in the package so you don't need anything else to start using the software. MinML is an ideal parser for XML-RPC because it is small, fast, and implements exactly the features of XML which are used by XML-RPC.
If you want to use a different SAX parser, you can do this by calling the setDriver() method in org.apache.xmlrpc.XmlRpc with the class name of the SAX parser.
Alternatively you can set the parser by setting the System property "sax.driver" to the class name of the parser you want to use.
java -Dsax.driver=your.sax.driver helma.xmlrpc.WebServer