The Java Architecture for XML Data Binding (JAXB) gives Java developers an efficient and standard way of mapping between XML and Java code. Java developers
using JAXB are more productive because they can write less code themselves and
do not have to be experts in XML. JAXB makes it easier for developers to extend
their applications with XML and Web Services technologies.
The JAXB Reference Implementation is now available in the Java Web Services Developer Pack (Java WSDP) 1.5.
Java Web Services Developer Pack 1.5
Download the latest
release, which now supports XML Web Services
Security, a preview of the Sun Java Streaming XML Parser based on JSR
173, as well as updates to existing web services technologies previously
released in the Java WSDP, and guidelines for developing client side web
services.
Java Architecture for XML Binding (JAXB) Specification 1.0 - Final Draft

API Documentation 1.0

More information:
Java Architecture for XML Binding (JAXB)
XML Downloads & Specifications
Java API for XML Processing (JAXP)
Java Technology & Web Services