XINS is an open-source Web Services technology, supporting SOAP, XML-RPC and REST. It consists mainly of an XML-based specification format and a Java-based implementation framework.
kXML-RPC is a Java ME (J2ME) implementation of the XML-RPC protocol built on top of the kXML parser. kXML-RPC empowers Java ME devices with a lightweight mechanism for exchanging data and invoking web services, in a neutral, standardized XML format.
JOX is a set of Java libraries that make it easy to transfer data between XML documents and Java beans. You can think of JOX as a special form of Java Object Serialization, using XML as the serialization format.