The Apache XML-RPC development team has released version 3.0rc1. "Version 3 is a complete rewrite of version 2. It introduces the concept of vendor extensions: by default, client and server are completely compliant to the XML-RPC specification. However, the user may enable certain non-standard features: streaming mode, support for all primitive Java types, nulls, DOM elements, JAXB objects, Serializable instances, and so on. Even more, the user may specify custom datatypes."