JAXB 2.0 Improvements over JAXB 1.0

Improvements

• Support for all W3C XML Schema features.
  (JAXB 1.0 did not specify bindings for some of the W3C XML Schema features.)
  
• Support for binding Java-to-XML, with the addition of the javax.xml.bind.annotation package to control this binding.
  (JAXB 1.0 specified the mapping of XML Schema-to-Java, but not Java-to-XML Schema.)
  
• A significant reduction in the number of generated schema derived classes.
  
• Additional validation capabilities through the JAXP 1.3 validation APIs.
  
• Smaller runtime libraries

Differences

• JAXB 1.0 provided validation at unmarshal time and also enabled on-demand validation on a JAXB content tree.
• JAXB 2.0 only allows validation at unmarshal and marshal time.